There has been some talk on Google Base on the Full Disclosure security
list. I've also seen on another blog about Google Base being a threat
to small businesses that do web hosting and the like (if you read the
Google Base FAQ, you'll see why).
Here's the FAQ about Google Base: http://base.google.com/base/about.html
Full-Disclosure Discussion on Google Base being used for malicious intent: http://seclists.org/lists/fulldisclosure/2005/Nov/0591.html