A cookie is a cookie and an IP address is an IP address
MediaPost Publications What Do BT And Copyright Infringement Have In Common? 07/08/2009.
Cookies, not IP addresses as claimed in the above article, are today used for behavioral tracking. IP addresses are used by ad networks for geo-targeting, for anti-fraud and auditing, and in some cases for presuming the type of company the user is coming from. They are not currently the basis for behavioral ad targeting at any major ad network or behavioral company. In fact, some behavioral ad companies in Europe very quickly delete IP addresses, or do not log them at all, in order to better comply with local law. Not saying there is no privacy issue with behavioral ads, as there certainly is – but it is the tasty http cookie that is at the center of this issue. Not saying there aren’t some new emerging business models focused on IP addresses, but this wasn’t the issue with PHORM. There has been plenty of ink already devoted to the privacy issues around the ISP behavioral model that PHORM championed, so I don’t intend to get into that here, but one of the points that the PHORM crew made in support of their model was that they didn’t keep IP addresses, while much of the rest of the industry did log and retain IPs.
Quite a muddle, so what is the lesson? Delete IP addresses quickly. Do so primarily because you don’t really need them long term and because they are a sensitive piece of data. Debate all day whether they are personal data or not, but clearly they are more of a hot potato than other data you hold because it can be linked to a user by law enforcement or a cooperating third party. Ask your ad network why they need to retain IP addresses of your visitors for the long term. Note that Yahoo deletes IP addresses after 6 months and some analytics vendors will eliminate the IP immediately – with no business impact.
The second reason to delete those IP addresses after a short term is that all sorts of people suspect you are doing funky things with them that you aren’t even doing!
