Have you stopped to consider that it may not be a problem on your end at all, but rather something that is unavoidable? For example, with Facebook, being as it is a social network where Facebook wants you to interact with other FB members, and where sharing information between users is one of their goals, it appears to be hardcoded into the system. If I go to my timeline and hover over a name in the contacts list on the right side of the page, or hover over someone's name under one of my posts, yes, it brings up an info window. That's what Facebook want to happen, and I don't think that you can disable it.
With the other sites that you visit, it may possibly be the very same thing. It all depends on how each particular site is designed, and it may be beyond your control, sad to say.