Unofficial Signal PIN FAQ

The Signal secure messaging app has started forcing users to set a new PIN, popping up a nag dialog saying Create a PIN PINs keep information that’s stored with Signal encrypted. They’ve done a terrible job of communicating why they’re doing this, so I went away and read a bunch of forum threads, GitHub tickets, blog posts and support documents and here’s my own attempt at an FAQ more clearly answering the questions which immediately occurred to me when I got the nag dialog this morning.