It isn't fraud. The legal requirements for such are subtle and numerous, but basically require knowledge and intent which are difficult to prove and unlikely in most or all of these scenarios.
Google has to do it's best to serve it's customers on both sides, those who display ads and those who pay for advertisers. Cheating exists, the mechanisms to mitigate that cheating aren't perfect, and each side loses some as a result. To claim that their imperfect anti-cheating mechanism is fraudulent is quite a stretch, and you'll be hard pressed to find a advertising facilitator which provides better customer service for such small sums of money.
I'm not so much concerned that they may make a mistake and close a legitimate account. I think not paying for ads already served, and not responding to queries about it, is enough grounds to take them to court. If Google wants to respond and make an argument as to why they shouldn't be paying for the ads the publisher has served, then they would be free to do so- the problem is they have refused to do so, and I think it is perfectly legitimate for a a publisher to take them to small claims court and demand that explanation.
So yeah, what I probably should have said is, "It smells of fraud, plain and simple". I am open to hearing Google's side of the story.
This is silly and incorrect. Some advertisers have budgets of millions, some tens or hundreds of dollars. Just like some content providers earn millions and others tens or hundreds.
Google has to do it's best to serve it's customers on both sides, those who display ads and those who pay for advertisers. Cheating exists, the mechanisms to mitigate that cheating aren't perfect, and each side loses some as a result. To claim that their imperfect anti-cheating mechanism is fraudulent is quite a stretch, and you'll be hard pressed to find a advertising facilitator which provides better customer service for such small sums of money.