Have you accidentally blocked social media sharing on your own site?
Check your own site(s). If you don’t already have a bookmarklet or app for social sharing go to the site for Chrome, Opera or Firefox (or which ever web browser you use) and take a look at the add-ons for social media. They are really nice for making social sharing quick and simple. I actually have a few of them. This way I don’t need to rely on the site itself to have social media sharing and better still, I don’t need to figure out how their social sharing works.