lucy24 - 9:30 pm on May 29, 2012 (gmt 0)
Another new one was the ahrefsbot.
I've had that one blocked for a long time due to misbehavior w/r/t robots.txt, so it was a surprise seeing the occasional "ahrefs" graphic in the top corner of wmt pages. What's it for? First showed up in November, with a peculiar habit of first getting pages and then getting robots.txt to, presumably, see if it was allowed to get the pages it had already gotten.