Check out this news item:
Latest Mydoom shows hackers using search engines for attacks
It's about Internet based worms making use of search engines to spread out. In the examples presented the worms search Google, Lycos, etc., for e-mail addresses and for vulnerable machines to hop to using specially-crafted search strings.
I was not aware of this trend of worms before so I agree it's new. Yet, I don't agree with any fear associated with this new brand of worms. These worms are somewhat novel in their approach. Yet, I think this approach is better for us (the good guys) rather than worse.