tips this news from GigaOm:
"Europe's proposed 'right to be forgotten' has been the subject of intense debate, with many people arguing it's simply not practical in the age of the internet for any data to be reliably expunged from history. Well, add another voice to that mix. The European Network and Information Security Agency (ENISA) has published its assessment of the proposals (PDF), and the tone is skeptical to say the least. And, interestingly, one of the biggest problems ENISA has found has to do with big data. They say, 'Removing forgotten information from all aggregated or derived forms may present a significant technical challenge. On the other hand, not removing such information from aggregated forms is risky, because it may be possible to infer the forgotten raw information by correlating different aggregated forms.'"