Many of the most valuable conversations around technology and many other fields happen on Twitter. If you’re not there you don’t really exist, especially if you’re just getting started in your field.

Facebook calls this “frictionless sharing”, which is their euphemism for silent total surveillance.

What most people don’t know is that the Like button tracks your browsing history. Every time you visit a web page that displays the Like button Facebook logs that data in your account. It doesn’t put anything on your wall but it knows where you’ve been. This even happens if you log out of Facebook. Like buttons are pretty much ubiquitous on mainstream websites so every time you visit one you’re doing some frictionless sharing. Did you opt in to this? Only by registering your Facebook account in the first place. Can you turn it off? Only by deleting your account.