If you listen or read the news about Facebook (and other Social Media sites) you should know that none of your private data are secure on such sites. The user an customer data are pure money for those sites! Such sites are off limit and prohibit on my own and also on most of my customer's Networks.
Yep, i know they aren't fully secure. However, it has been a very long time since a tab has just opened up by itself for me, and I can't tell if I just happened that I clicked on a microsoft ad or if it was truly malicious and acted on its own.
It is no News that such sites are not only "... they aren't fully secure", they're totally insecure, and the users, members and customers of such sites giving their data freely on their own will to such sites! That not only applies to Social Media sites, it applies to a lot more sites, special to those which are 'temporarily' or permanent storing Customer and User data to their own Servers. That also applies to sites like TeamWork and others, including to that so-called Cloud storage sites.