Uh, so are you...you have a part interest in it. When disreputable site owners steal money, it hurts everyone. It hurts in available revenue. It hurts in advertiser trust...that's a big one folks! Yes, Google may find the cheating sites but it takes time. The sooner they get shut down, the quicker they disappear which means more faith by advertisers. Do you know what happens when advertisers have more faith in the system and the clicks? Well, there are more of them, and the bid goes higher. Do you know what that does? How about higher ePC. So don't tell me it's all Google's problem. Look at all the threads in here about people bitching about their earnings. Yes, part may be the economy. But when the economy is down, advertisers are even less willing to put money into a system if they know there is a high percentage of cheating sites.
Speaking as an advertiser rather than a publisher - I just nip over the fence to the adsense forums from time to time to have a look at what you boys are up to ;-) - I have from time to time - occasionally I've after running a report on where my ads are showing I've seen something that's too cheeky to be ignored, so I both block and report. And very occasionally I've seen something when I've just been surfing that has made me wince, so I've reported it.
Leave it to the professionals. You know that a lot of large organisations will actually look into why an informer is doing what they do, if they seem overly eager to shop others for something they often get investigated. Because its human nature to pretend that your against something when you can be one of the biggest culprits, they know this happens so without you really realising they will check out why someone is reporting people so often. And if you believe in what goes around comes around then you will know that life has a habit of making you pay for negative acts done to others.
If a person is abiding by the rules he shouldn't be concerned at all with Google looking at his site. I know they've looked at mine.
There's plenty of ways to cheat google. -Adsense with "NO" content. -having a giant arrow pointing at the adsense advertisment etc. I know a lot of you people are saying that its their job and you take care of yourself, but what you don't realize is that the less adsense cheaters there is, the higher the CTR will be.