FreeBSD 13.0 released

At that time a guaranteed way to panic the system was to remove a USB drive while it was mounted. Just accidentally jiggling it was enough. The bug had been there for years, and their excuse was that the system was fundamentally designed with the assumption that drives won't disappear while in use, so just don't remove a mounted drive. It verged on a WONTFIX response. Ironic since FreeBSD boasted of getting USB support before Linux did.

Then Matt Dillon fixed it in Dragonfly BSD (which I used for a while).