What is happening on linkedin? Are people who they really say they are?

Just recently I have had quite a lot of people linking to me, with some interesting images, but are they real?

For that matter on social media are you the reader real?

US Bankers, Insurance executives and even the recruiters, have as their web sites facebook pages and the last three invitations that I accepted appeared respectable, but all went to a url called the fit man......

Decidedly odd, and I have the image that social media is being overrun by fake accounts and fake people.

I guess I should shut up and accept all, just like facebook does, and build my brand shouldn't I?