Telling mobiles (in specific: BBT)

Due to a technical change how "tell" and mudlle interact, you cannot use tell
anymore to inquire if certain mobiles are alive. That this was possible in the
past was never an intended feature but a... hum... "feature".

Tell now only works on mobiles that are actually intended to receive tells.

Where this is highly relevant are, for examle, the three trolls Bill, Bert,
and Tom as non-Trolls cannot determine anymore from afar if they are alive or
dead.