[tomwhipple]

Root cause: Usability. It's difficult to quickly set up. But there are (at least) two components to this:

1. Portability. How do I manage keys across my computers, phones & tablets?

2. Ease of use. What do I do to set this up? Most common clients don't support PGP out of the box. Even once plugins are added, they are complicated to use.

As a result, no one uses it. So, if you want to start, you need to convince your friends/colleagues to also use it.

I've recently started signing email from my home computer as a hint to others to do the same. So far no takers.