DLP for document content

I have to handle a problem regarding content in files which should be blocked.

What my customer wishes is to block any file which would contain ther users and/or customers private informations like credit cards info, CPF (similar to SSN), e-mails and other stuff.

What would be the best way to treat this case? I couldn't find some info about how to configure it, but I was thinking about document fingerprinting where my base would be some files containing separate data regarding these kind of info. 

Thanks.