I've just created a sample letter (in German) to Hetzner. I urge everyone who has a HA setup or is interested in this to fax it or send it to Hetzner:
Hetzner Online AG
Fax +49  9831 61006-2
Edit: I've just added a version in Word format as well. I'm trying to get an English version prepared as well.
Edit : Thanks to toodles we now also have English sample letters.