I know exactly how some people got banned by Adsense, stealing the content of another's website and calling it their own. A well-placed complaint about the Adsense publisher's website to the Adsense team resulted in the website being banned from Adsense almost immediately after my complaint was made this past week.
He was out-ranking me in Google using my content exclusively. I suspect the copyright violation to Google Search will also get quick results.
It's obvious to me he was banned, because he pulled Adsense off his website, replacing them with an ad server known for producing very low ctr and cpc for publishers. They are the company banned Adsense publishers use when they're tossed from the Adsense program.
I had been making a bundle when I was in the #1 position for Google Search, before he launched his website with my content and took #1 based on his domain name match to the keywords in my content. The only way he'd pull those high income ads was if he was forced to pull them.
This is one of the stories from the other side of the "Banned By Adsense" issue.