If you entrust your data to others, they can let you down or outright betray you.

The problem is, we're moving to software-as-service, which can be yanked or transformed at any moment. The ability of your PC to run independent code is an important safety valve.

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.

All sorts of factors contribute to what Facebook or Twitter present in a feed, or what Google or Bing show us in search results. Our expectation is that those intermediaries will provide open conduits to others' content and that the variables in their processes just help yield the information we find most relevant.

Digital books and other texts are increasingly coming under the control of distributors and other gatekeepers rather than readers and libraries.

(With the DMCA) you have the sword of Damocles,