asciilifeform: ThickAsThieves: yeah, why bother with cheap and effective solution costing pennies (big red 'stop' buttons on walls, guaranteed jail for false alarms)
asciilifeform: perhaps a miniature induction heater.
asciilifeform: someone could make good money selling a means of melting a glass rod over a (recessed) screw head and then breaking it.
asciilifeform: i believe the ancient greeks used something similar, with a broken clay pot☟︎
asciilifeform: two spies meet, and match up the pieces
asciilifeform: recall the rifle shell sawed in half from ww2 partizan movies
asciilifeform: i kept waiting and waiting for the modern internet crackpot community to pick up 'scalar waves!' and 'torsional waves' crap from the '90s