From an email I received from Twitter recently:
We've provided more details about the information we collect and how we use it to deliver our services and to improve Twitter. One example: our new tailored suggestions feature, which is based on your recent visits to websites that integrate Twitter buttons or widgets, is an experiment that we're beginning to roll out to some users in a number of countries.
That's despicable. I don't have any social media buttons on my site and I'm now happy I never put them in. I did consider it at one point, but just didn't have the time so left it. Definitely not putting them in now.
What I do use is the "Share Article" functionality built into Squarespace (affiliate link), which doesn't track anything. Hover over the link below this article for an example. It makes it easy to share without tracking you. In fact, the only tag on this site is for Google Analytics and I'm considering removing that as well as Squarespace provides nice analytics out of the box.
If you want to prevent Twitter and anybody else from tracking you and invading your privacy, use Ghostery.