Now that click fraud suits have mostly come and gone, the next big wave of riches that class action lawyers will extract from the search engines is for false advertising.
Scenario / Pop-quiz:
So the $64M question: Who gets sued?
Answer: Everyone!
That's my early prediction for 2007 - a ton of false advertising suits against Google, the CPA / affiliate networks, the merchants, the affiliates and anyone who ever ran such an ad on their page.
Get in early while the gettin' is good...