MonkZ

I hope they update their protocols

German car driver here. I don't use it as signal of anger, but as hint, that the driver in front has to refocus on the traffic again. (Others may still angry-honk of course)

On systemd enabled systems, try "loginctl lock-sessions" as udev cmd. It should work on common desktop environments. If you have something custom try xss-lock to react on the lock-sessions signal.