When Opting Out of Ad Tracking Doesn't Opt You Out

jfruh writes "Privacy blogger Dan Tynan couldn't help but notice the ads targeting his web browsing for a plus-sized women's clothing store, not least because he's neither a woman nor plus-sized. But trying to figure out why those ads kept popping up in his browser led to some disturbing discoveries. He had opted out of targeted Google ads, and at first glance the ads seemed to come from Google — but digging deeper, he found that Google's DoubleClick was only the intermediary, which meant his opt-out didn't apply. And his opt-outs from other ad services seemed to have vanished."