I believe you will find that these bots are operating a pre-programmed search. They are able to search for any parameter in an object's properties or for people (generally by UUID). I have been watching this develop over the last 18 months. The account names being used were all created in May of 2009, and include user names starting with Brenden, Natalia, Selena, and Rihana at the moment. Clearly the person operating these searchbots has both an agenda and a great deal of effort and money into this. Unlike Beggar bots and Phishing bots, these bots are not obviously malicious, but just as clearly, anyone wishing to intrude on someone else's privacy with automated searches that run grid wide, is not likely to wish someone well.