Google announced they will begin requiring many of their advertisers to ensure their web site practices and technology is in accordance with rules to make the AdWords marketplace "safe, fair, and trusted marketplace" for their searches.
The new rules will require a (1) valid SSL connection when collecting payment and certain financial and personal information, (2) a method to to discontinue direct communications (opt out) when collecting information that can be used for communication and (3) a policy that is available to their web site users for disclosure before visitors submit personal information (privacy policy).
These three new requirements go into effect May 17, 2011.
For more information on the privacy policy and disclosure information, see this help document and for more on the SSL requirements, see this help document.
A WebmasterWorld thread is very skeptical that these new policies will prevent shady advertisers from advertising on Google and scamming Google's searchers and users. One advertiser said:
Either way, requiring SSL means nothing at this point, SSL certificates can be acquired for peanuts or even free. They should have been more specific about the type of the SSL certificate.
Forum discussion at WebmasterWorld.