Hello, I run a user driven website, here people add content, I am worried that Google may ban me for duplicate content. My question is will Google ban the whole domain or only that page? Thanks.
I don't see why you would be banned for duplicate content from your users adding the content. You might drop in the search engines though for what your keywords are.
Probably not unless someone files a DMCA with them. You might see lower rankings on a page per page basis.