In adsense many of times new and even old publisher get banned in regular period of time. In which many acclaimed that Google banned them simply without any prior reason. I would like to point out few major reasons to get banned.
Lack of Knowledge
As we all know that Google is much strict regarding Terms of Conditions and its privacy. According to my own survey 75-80% publishers get banned by exploiting terms & conditions. Thats why i suggest every new user to read out all TOS carefully.
To obtain high number of clicks most of publishers tend to place ads on whole page. At times that gives some amount of invalid clicks and raises up CTR Rate above 100% which is totally un acceptable.
Copyrighted Content & Material
Copyrights are also another reason that Google never allows its publisher to use any content & material which is strictly prohibited by its orignal owner. Unless for duplicate content it gives only few cents.
These are general banning reasons of publishers in Google Adsense.