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Netflix Prize Sequel Cancelled Over Privacy Concerns 65

An anonymous reader writes "Netflix just announced that they have cancelled the sequel to the Netflix Prize, which was promised last year. Netflix made the choice after they were sued over privacy concerns. The prize involves releasing large amounts of data about users' movie preferences, which raised concerns from the Federal Trade Commission and a lawsuit from KamberLaw LLC. Netflix's Neil Hunt said, 'We have reached an understanding with the FTC and have settled the lawsuit with plaintiffs. The resolution to both matters involves certain parameters for how we use Netflix data in any future research programs.'"
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Netflix Prize Sequel Cancelled Over Privacy Concerns

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  • by LostCluster ( 625375 ) * on Friday March 12, 2010 @02:47PM (#31455396)

    From the linked to previous story...

    If a data set reveals a person's ZIP code, birthdate and gender, there's an 87 percent chance that the person can be uniquely identified

    Why does Netflix need to release something as precise as a birthday in order to make movie recommendations? I mean, TV ratings are done in demographic groups. Couldn't Netflix get away by just stating a birth year?

    • Maybe they are consulting the Zodiac astrology?

    • a whole lot more on the people to identify them from those three pieces of information.

      As in, you would need to know which house has the account, then guess among all the netflix in that zipcode.

      I suppose you could stand outside, but I doubt that there is 87% chance unless you know other supposedly private information.

      I don't see how exact birthdate matters, how would you confirm it when looking at people? Birthdate x/y/z lives at 144 Amazing avenue? Really? and what gave that away?

      • by LostCluster ( 625375 ) * on Friday March 12, 2010 @03:21PM (#31455882)

        Let's say you have a job. Your boss, by law, needs to see and retain a copy of either your drivers license or passport, either one of which identifies your birthdate, address (which contains your ZIP code) and gender.

        Now let's say he downloads this Netflix data... he's got enough info to be 84% sure that the only record that has your birthdate, gender. and ZIP code, is you. Worse yet, if he had your ZIP+4, the only way there'd be any ambiguity left is if you live with a twin.

        • And even if there are 2 matching accounts, a little bit of guesswork from information known about the person can remove the ambiguity. Look for foreign-language films if they are an immigrant, films or shows that appeal to their occupation (Dilbert cartoon or the IT Crowd for someone here, The Real World or Jersey Shore for someone at Abercrombie) or hobbies (musician, car person, etc), and boom, suddenly you know that the applicant watches softcore porn/disney shows/GLBT interest film.

        • Re: (Score:3, Informative)

          by winomonkey ( 983062 )
          I am curious which passport you have that includes your address. If I recall correctly, mine does not have an address in it. To verify, I looked to see what goes into a passport [wikipedia.org]:
          • Photograph
          • Type [of document, which is "P" for "passport"]
          • Code [of the issuing country, which is "USA" for "United States of America"]
          • Passport No.
          • Surname
          • Given Name(s)
          • Nationality [which is "United States of America"]
          • Date of Birth
          • Place of Birth (lists only the state followed by "USA" for those born in the United States)
          • Sex
          • Date of I
          • by Splab ( 574204 )

            So you have a job where your employer doesn't know where you live?

            • Actually, they do not know where I live. They need a mailing address, not a home address, and that is what they have. I use online systems for most of my regular documents from them, and use interoffice mail for most of the rest. There is a rare occasion where they send something to my mailing address (tax forms, etc). None of this really matters, anyways, as the Netflix account is in the wife-to-be's name.
        • 99% chance that your boss doesn't know enough to mine the data, and he wouldn't care what movies you've been watching even if he did know.
          • Re: (Score:3, Insightful)

            by retchdog ( 1319261 )

            For now. If this kind of data-leak became common, you can bet there would emerge specialist firms/consultants to do the mining, perhaps as a value-add onto a more general background check.

            Vigilance.

    • Re: (Score:3, Insightful)

      by FunkyELF ( 609131 )

      Why does Netflix need to release something as precise as a birthday in order to make movie recommendations? I mean, TV ratings are done in demographic groups. Couldn't Netflix get away by just stating a birth year?

      I was born on Dec 4th so I am partial to movies about Pearl Harbor.

      I'm sure people born on or around Dec 25th feel differently about Christmas movies than others.

      You comb through enough data you'll find patterns. Who knows.

    • Because there is a higher probability that a girl will rent 16 candles on her 16th birthday.
    • For that matter, why the person's zip code? I can understand that geography may play a role in people's tastes (coasts vs central America, urban vs. rural), but the full zip code is overkill. Just give the decade of birth and state of residence, and if necessary the size of the town/city the user is from, bucketing them into groups like 100-1000, 1000-10000, etc). That should give enough data (approximate age, geography, urban vs. rural vs. suburban) to the researchers without being specific enough to ident

      • by Splab ( 574204 )

        Because that would be pretty much useless. I'm from Denmark, within a radius of 15 miles from my home you will find some of the poorest people in Denmark and some of the richest, several 100 zip codes (Copenhagen), and taste varying from the finest art to hardcore rave.

        You need to be way more specific than what state the person lives in, ZIP + quater and year of birth might be "enough".

        • I think what he's saying is that it would be sufficient to label a person as being from Copenhagen. Don't forget, the age and zip code are secondary classifications. The primary data is the list of movies they watch. So, you don't need the zip code to determine who enjoys the finest art and the most hardcore rave. They are already distinct.

    • by zkp ( 1634437 )
      In the original netflix competition the data they did not release birthdays, zip codes or gender. Every movie and user was given a unique (presumably random) id. Essentially the data you had to work with was a bunch of tuples: (movie id, user id, rating (1-5), date) Netflix claims they even added some random noise (changing the dates/ratings a little bit) to preserve anonymity. Turns out even this isn't enough to guarantee anonymity...it turns out you can cross reference this data with imdb to look for
    • by zkp ( 1634437 )
      In the original netflix competition the data they did not release birthdays, zip codes or gender. Every movie and user was given a unique (presumably random) id. Essentially the data you had to work with was a bunch of tuples:

      (movie id, user id, rating (1-5), date)

      Netflix claims they even added some random noise (changing the dates/ratings a little bit) to preserve anonymity. Turns out even this isn't enough to guarantee anonymity...you can cross reference this data with IMDB to look for similar dat
      • Are you sure about this? I briefly looked over the paper and found it unconvincing. The first half is mostly bold claims like:

        With 8 movie ratings (of which 2 may be completely wrong) and dates
        that may have a 3-day error, 96% of Netflix subscribers whose records
        have been released can be uniquely identified in the dataset.

        And then the second half is a tremendous amount of math. I didn't see any evidence that the authors actually de-anonymized a single person, let alone 96% of them.

        Besides, how do you down

    • My gf knows a lot about astrology, and believes it has an influences on your personality. A good recommendation engine could use this information along with everything else. Your birth year is significant, but it doesn't run 1 Jan to 25 Dec. I'm not sure if this is based on the Chinese calendar or if that's a separate data point... but in order to identify your sign and year, you need to know the exact date.

      I don't lend astrology much credence, but if you're going to tell me it doesn't work I'd like some

  • by pwnies ( 1034518 ) <j@jjcm.org> on Friday March 12, 2010 @02:47PM (#31455400) Homepage Journal
    This is definitely a sad outcome to all of this. However, couldn't Netflix just update their EULA and/or have an opt-in for users who want to make the experience better?
    • Well, Netflix needs to at least start over because the data set they disclosed is the point of the issue here.

    • Why don't they munge the privacy info, instead of saying a account belongs to John Smith, say it belongs to 1122113.

      No one except netflix will know who exactly 1122113 is.

      • This is exactly what they do.

        The problem is (and someone figured this out), John Smith might ALSO have a IMDB account. And if we compare the date and star ratings from his IMDB account with his Netflix accout, we can accurately figure out who 1122113 is. Some people actually did this.... that is, took the completely anonymous ratings, and used those ratings to match up with an unanonymous source, and figure out information.

        So Netflix is doing it right, I think. It's just that the Netflix data can be used

        • by zkp ( 1634437 )
          See the paper "How to Break the Privacy of the Netflix Prize Dataset"

          I disagree that Netflix did it right. We live in a day and age where there are many sources of auxiliary information publicly available (IMDB, voter registration, etc...). Any attempt to preserve anonymity must take this into account. All to often companies leave out specific pieces of information (name, DOB, Zip Code etc...) and hope that what remains is anonymous. No one could ever identify me based on just a couple of movie ratin
    • That is possible, but they still can't do the study they want to do today, because the information they have collected up to the point people start checking the tickyboxes was collected without the permission to release it.

      If they implemented the opt-in this week, they'd start collecting data and they'd probably have some useful data NEXT year.

      However, that also leads to some interesting questions about data validity. A valid study uses truly random data from a full range of customers. The new study, if d

  • Wow (Score:5, Insightful)

    by Pojut ( 1027544 ) on Friday March 12, 2010 @02:49PM (#31455438) Homepage

    I don't know if people are just paranoid or what, but they seem to be intent on protecting EVERYTHING nowadays. Next thing you know, people will get sued for asking whether you put the toilet paper roll facing away from the wall or towards it.

    For the record, it's away from the wall, you savages.

    • The libraries here post signs saying that they'll strictly protect your privacy, but if there's a law enforcement person who cites the PATRIOT Act, they have to give it all away.

      • by Pojut ( 1027544 )

        Not sure who's sig it is, but someone around here has it set to:

        "Knock Knock"
        "Who's there?"
        "Under the Patriot Act, we don't have to tell you."

        It would be awesome...if it wasn't so true |:/

      • The libraries here post signs saying that they'll strictly protect your privacy, but if there's a law enforcement person who cites the PATRIOT Act, they have to give it all away.

        That is precisely why good library circulation software does not preserve that information indefinitely.
        If you need to be reminded that you already read a book or rented a movie 3 years ago, you could probably stand to see it again. The convenience factor is minimal compared to the (almost) worst case scenario of a federal investigation. (The worst case is of course when they decide to skip the investigation.)

    • There's really only one thing people get sued for: having money.

    • Re: (Score:3, Informative)

      by fahrbot-bot ( 874524 )

      ...you put the toilet paper roll facing away from the wall or towards it. For the record, it's away from the wall, you savages.

      Assuming "away" means "over", then you must not have pets. A kitten can easily unspool a whole roll like that. Having it facing the wall (or "under") prevents that.

      Perhaps that makes me a savage, but at least I'm a neat savage. :-)

      • by Pojut ( 1027544 )

        I have a toothy orange two year old cat named Fizzgigg (yes, after the toothy puffball from The Dark Crystal...it's a very appropriate name for this animal, I assure you). She leaves the toilet paper alone...her thing is hair ties.

        Toss a hair tie, and she'll chase after it...and bring it back to you. Over. And over. And Over. She plays freakin' fetch, lol

        • The girlfriend has a cat that will take your straw out of the cup (sometimes not knocking it over) and will bring it to your feet over and over playing fetch.

        • by adolf ( 21054 )

          Right. Hair ties are fragile, though, and chewy -- the cat (my cats, anyway) tend to bite them in two, and then they're no longer interesting.

          Try a milk ring sometime. You know, that little red/orange/yellow/blue ring under the cap of a gallon of milk. I've got a cat that will chase one of these around, independently, for several unbroken hours before he gets bored with it, which is really quite something since he's approximately bloody ancient these days.

          And: They're free with every gallon.

          (-1 way off-

      • That and the fact that when you use the double rolls and the over placement they tend to bump into the wall and the friction causes the paper to tear prematurely. So then you have to make a decision. Is that enough sheets, or do I want to try to stack it on top of what you already have, and then balance it while you try to get it behind you. (Sometimes there are multiple attempts stacked...) If it falls off in the process (you may not notice... what I have heard anyhow) you won't have enough paper for it t

      • by Uzuri ( 906298 )

        My cats must be smarter than your cats -- they're quite capable of emptying a whole roll no matter which way it's spooled. Then they open the cupboard and take all the stored rolls out and do them in as well.

    • There's a reason they call it a guily pleasure.

    • For the record, it's away from the wall, you savages.

      Your the savage I have a stream of cold water shoot up my ass followed by a nice breeze since there is no wiping I don't even have to wipe my hands. High 5 anyone.

    • Unless you have cats.
    • I don't know if people are just paranoid or what, but they seem to be intent on protecting EVERYTHING nowadays.

      That's GOOD. I'm not happy that the second Netflix prize is canceled, and that the data of the first prize has been removed from UCI, but protecting privacy is IMPORTANT.

      Anonymizing data (ie while keeping all other statistical properties intact) is a very hard problem. Solving it properly is a huge prize itself that would revolutionize Science, and there's no reason to blame the researchers

    • For the record, it's away from the wall, you savages.

      We have a kitten. Towards the wall is the only way to keep her from unrolling an entire spool.
      Unless you'd argue that forcibly restraining a kitten is the less-savage option. :) Other than TP, it's the safest and sunniest room in the house to leave her alone in.
      But maybe we're just paranoid.

    • I don't know if people are just paranoid or what, but they seem to be intent on protecting EVERYTHING nowadays.

      It's a reaction because of organizations that insist on protecting nothing. The douchebag orgs kind of ruined it for everyone.

  • by T Murphy ( 1054674 ) on Friday March 12, 2010 @03:09PM (#31455722) Journal
    I bet there are thousands of guys out there scared to death that someone will find out they rented Twilight (for the girlfriend, honest!). I'd rather be known as a lawyer-happy jerk than a Twilight fan.
    • Ok, I admit it. I rented Twilight. Not for my wife, either. I was just curious. You know.... an experimental phase.

      You know what I learned? I'm getting old. 'Cause that movie sucked hard. Holy crap, was that one boring, boring, boring movie. I can't really convey how terrible it was. And the way that I know I'm now officially getting old is that I can't even see how a pre-teen could find it entertaining. It didn't even really do a good job of conveying teen angst, or alienation, or much of anythi

      • My wife and I just rented it, too. Just to see.

        I stopped watching at the vampire softball scene. Ugh, so bad.

      • No, no, this is Slashdot, it's OK to vent. Tell us what you REALLY think about it. You sound ambivalent.

        If it wasn't good enough to be bad, was it at least bad enough to be good? In a "Plan Nine From Outer Space" / Mystery Science Theater 3000 kind of way? Could Mike (or Joel) and the 'bots save this snoozefest and turn it into a laughfest, or at least make it chuckle-worthy?

        Or was it, as they say, just a large sack of suck?

        • by spxero ( 782496 )

          I made it to about minute 45 before I couldn't take anymore. If a movie can't get *somewhere* in 45 minutes, it's really just bad.

          There wasn't enough dialog for MST3K to work with. GP was right- it's just a long, boring staring contest. How this crap is even popular is beyond me. My wife's friend swore up and down that I need to read the books... no thanks. That's why I want to watch the movie- reading the book series for a couple weeks appeals even less than sitting through a 2hr+ movie.

          On XKCD suck scale

    • Re: (Score:1, Funny)

      by Anonymous Coward

      Just wondering, what's your zip code and birthdate?

Understanding is always the understanding of a smaller problem in relation to a bigger problem. -- P.D. Ouspensky

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