Comments with Facebook Auth User and anonymous I'm working in a site that needs some special behavior for comments.

The user will have anonymous and users connected with Facebook. 

For comments, the site needs to allow anonymous comments posting but if the user is connected with Facebook the page will permit to the user make the comment with Facebook or as some anonymous user.

I been googling for a couple of hours some module that provides this functionality out of the box but I was not able to find one.

Does anyone knows some module to recommend me ?

Thanks in advance !
You could try the disqus module, which uses the disqus service.

It is arguably better than using facebook comments because it also allows people to comment using other social network accounts, not just facebook.

It also allows guest commenting.

Depends on your requirements though as to whether or not that is an acceptable solution.