Having read through lots of threads about accounts being banned for illegal clicks ect i could not find a single post that said "i got banned for modifying ads" or playing with the java script or saying "click the ads support the site". This leads me to think there are only 2 ways to get booted. 1 Click on your own ads or get friends to click on them. 2 An adwords account holder who buys ads that have shown on the offending website contacts google and makes a complaint regarding breaking tos conditions. I have not seen any proof that any member from this forum who has complained to google about a website has caused that publisher to be banned. If a publisher has illegal clicks its fraud. if an adwords account holder complains that google are gaining a share of revenue its fraud. can anyone prove me wrong ?
I think you only hear about "illegal clicks" because its a) Easy to admit that you "accidentally" clicked on your own ads which caused the band b) "Somebody" else clicked your ads repeatedly and got your account banned. Illegal clicks is just a nice scapegoat. I highly doubt it that anybody would come and post in forums admitting that they did something wrong and that they were actually planning to try to fraud Adsense.
Illegal clicks is a Google catch-all term. If you break the TOS using any of the means you mention, the clicks are illegal since they are generated outside the TOS.