Msg#: 3686239 posted 8:48 am on Jun 29, 2008 (gmt 0)
Here's a bit of an unusual post from Matt Cutts on the official Google blog. I do wonder why it was published at this particular moment (I'm always looking for that hidden motive these days) but I do appreciate the look behind the scenes that he gives.
IP and cookie information is important for helping us apply this method only to searches that are from legitimate users as opposed to those that were generated by bots and other false searches. For example, if a bot sends the same queries to Google over and over again, those queries should really be discarded before we measure how much spam our users see...