I got a couple emails from people asking me why they got banned from adsense. It was actually the barcamp post that led them mailing me thinking that am a google employee
Am not a google employee(would have been lucky if i was) but anyways i mostly know a few reasons why someone gets banned from Google adsense.

Here might be one or more reasons why your account was banned in Google adsense program.

You click on the ads - Your greed towards earnings when you are new to adsense, might have got your hands to click on the ads which you published in your website. This would be just foolishness if you click on your own ads, and its the very basic reason why most of the publishers get banned from Google adsense.

Encourage people to click - There are still many sites which still allow some sort of freebies to people who go through a procedure of adsense clicking. This is not allowed according to Google adsense policies. Asking for clikc by saying “Support us by clicking the ads” can easily get you banned.

All content is not allowed - Many a times, people don’t know which type of content is allowed to have google adsense and which is not. Here are some niches and types of content which can not be accompanied to be in a website with Google adsense -

• Pornographic Content
• Hacking/Cracking Content
• Gambling or Casino related Content
• Any other illegal download type Content

Google just don’t like it and don’t support placing ads in those type of sites. If you are placing in greed, your whole google adsense account is in danger.

No tricks to be played - Don’t place the ads in any tricky ways, by mixing up colors, or placing in such places which forces the visitors to forcibly click on the ads rather than navigating through your site.
Pop-up’s, pop-under and emails can not have google search boxes or ads in them. Any private pages also should not have Google ads in them.

Traffic/Click exchange programs - You think this would really generate some good revenue for you? Yes it does give you good money, but only until you get noticed by Google adsense team and you get banned. Traffic exchange programs on pages that have google ads, or exchanging adsense clicks with others through some programs or softwares will lead to a ban. So be careful and away from these things.

These are the reasons which i majorly see people getting banned in Google adsense for. If you know any other reasons, share them below.