It's super easy to get somebody's adsense account banned, even without clicking on the ads!
Unlike YPN, google doesn't have a concept of "authorized domains". That means you can easily lift ANYONE's adsence code and put it on a bogus site like geocities. Add some verbage like "Help support our site by clicking on a sponsor below". Then report the site via the delivered ad.
I unfortunately, know about a dozen sure-fire ways to accomplish this as some chap was gunning for me and wiped out 6 or so different adsence accounts my LLCs, CORPs had.
Each and every time he'd email me bragging that he took me out again! I have even tried to explain this to google but it falls on deaf ears!
The only response you'll ever get from google is a canned response that doesn't even acknowledge the problem.
BTW, one site did close to $500 a DAY with adsense.
I've lost all faith in them. So much for their "Do No Evil" motto.