Basically, every time you visit a site that has a follow button, a “tweet this” button, or a hovercard, Twitter is recording your behavior. It is transparently watching your movements and storing them somewhere for later use. Right now, that data will make better suggestions for accounts you might want to follow. But what other things can it be used for? The privacy implications of such behavior by a company so large are sweeping and absolute.
That’s pretty shitty of Twitter if I am honest. I have been using the embedded Tweets and the follow buttons on this site without knowing that Twitter did this. So I am sorry about that. I took some time this morning and removed those embeds everywhere I could find, if you see one shoot me the URL of the post and I will remove it.