Facebook® has made it easy for website owners to access information from your Facebook® account. A lot of websites are making use of this. For every page you visit on such a website, the website sends a message to Facebook®, asking for your data. As a side effect, Facebook® gets a record of your browsing history on these websites.
I am not comfortable with that.
This is what I did to opt out:
Greetings
* This list might not be complete, if you know about more domains, I'd be very happy to add them.
here is a direct link to the filter file if you just wish to see it.