Re: Like-block
If I actually had a Facebook, Twitter, etc. account I'd be more concerned. Even without such accounts, I do appreciate websites like www.schneier.com that block social network tracking by default, using
http://panzi.github.io/SocialSharePrivacy/
If the "like" and "share" buttons exist, and aren't greyed out, well, that tells you something about the website you are on.
(Note, in case I was insufficiently clear, a site with a "like" button is tracking you whether you have a Facebook account or not. Yes, you can block it, but wouldn't it be nice for the site owner not to throw you to the wolves for a pittance?)