How to allow social login without those sites being able to track the user

Hi there,

I’ve tried searching the web for this but didn’t find an answer. I run a small bbpress-forum and have implemented a little plugin that allows me to have one sub-forum where all user names are anonymized automatically, including in quotes etc.
This is the forum area where they can share stuff they don’t feel they can share openly, stuff they might be ashamed of etc.

Now for convenience of my users (and to lower the entrance barrier), it would be nice to be able to offer them the option to login via facebook, twitter, wherever they might already have an account.

But because of the special nature of that one sub-forum, I need to be sure that those social networks can’t access the sites/the content those users are browsing.

Perhaps those social networks don’t track this stuff anyway, but I suspect they do. If so, how to prevent that from my side? All I’ve found so far are articles about how a facebook user can prevent another site from accessing his data, but very little about the other way round.

Perhaps those social networks don’t even track the content/sites to start with, then the question might be irrelevant. But I highly doubt that is the case. So, any advice?

Thx, Niklas

P.S.: This is a general question, which is why I didn’t put a link to my site or post it in a specific plugin sub-forum. I hope this is ok with you.