The guy gave his site URL, so of course I went over to it to have a look. I'm no expert, or even very knowledgeable about Google or AdSense, but I have an idea of what they don't like. One thing I know they don't like is 'AdSense Sites'...people setting up sites specifically to generate an income from Google, with virtually no useful content. You really can't blame them either.

I won't go into a lot of details about the site in question, but when you have pages that are devoted to only links, with no content whatsoever, then Google will have a problem with it. This site had a 'Best Links' page, and also a 'Link Exchange' page. Couple that with no content, and you've got a problem.

I don't make a lot from AdSense, but I do like having the option of using the ads whenever I'd like to. It seems to me, at least from what I understand of the big G's terms, that they don't really ask for anything that isn't reasonable. They just like trying to ensure that their ads (customers ads) display on relative, content rich, respectable sites. That's really not asking much. I use AdWords occasionally, and I'd like knowing they're reaching sites that might produce for me...not just a link farm site.

So if you're putting up a site for long term income, one that gets better everyday because of the added content, then you'll never have to worry about Google coming down on you. As your site/content grows, so will your traffic and income from AdSense.

You might be able to generate heavy, 'ill-gotten' traffic, and a decent AdSense income for a while, but they will catch up with you. It's just a matter of time.