Adsense Policies are well laid and said on the Adsense Help Page. Adsense always try to keep the pace with their policies and so they remove the site which they think is breaking their policies. The most cases why site is banned is because of nudity and rasical discrimination. Lets forget that all stuff and let concentrate on what will you do when you see a site having Adsense code and violating policies.

Beware that using a copyrighted content on your blog might end up losing your Adsense account if the Copyright owners reports.

Some regular issues found are

• 1. Copyrighted Content of your blog without any permissions or notice
• 2. Un authorized placements of ads on your blog or site
• 3. Ad Complaints

So if you find any site breaking the mentioned Adsense Policies you can report to Adsense at Report a Policy Violation Form and provide the details asked.