Need a clear explanation about being banned by Google

I see some websites copy other sites' contents yet they still have good PR. how come is this possible?
please help me understanding this.

thank you very much

 

They may have backlinks from high PR sites.

 

They must have lots of web content and backlinks in order to rank high. Once they got ranked high, their contents will be crawled earlier than original sometimes.

 

Site authority and reputation could have something to do with it. You can write and post an article on your site and then post soon it too on top article directories. Few days later when you search that article, you may find the article posted on top article directories are on top of the result.

 

Well i feel that the main reason for getting banned in Google is there must be many posts or innumerable promotion done from the same IP address on the same site.

 

Yes I agree with "linc". They might have quality back links and their content might get index earlier than the original one.