Jonathan Zittrain

With the rise of software patents, engineers coding new stuff - whether within a large software company or as kids writing smartphone apps - are exposed to a claim that somewhere a prior patent is being infringed.

I don't know how much thought is behind it, but it seems to me highly effective the way that Facebook will let somebody tag a photo with a friend's name, then others who are a friend of that friend can perhaps immediately see the photo, and the friend, in the meantime, has a chance to wander back and un-tag it.

Early in the 1990s, I flew alone in a dandelion-yellow, single-engine, 180-horsepower Piper Cherokee from Westchester County Airport in New York westward to the Rocky Mountains, landing and refuelling a good many times in middle-sized cities and towns along the way.

Every time you log in to Facebook, every time you click on your News Feed, every time you Like a photo, every time you send anything via Messenger, you add another data point to the galaxy they already have regarding you and your behavior.