The “Siren Padlock” adds a 100dB* alarm to a hardened steel and zinc-alloy padlock. The alarm goes off for ten seconds every time the padlock is moved or tampered with, making it difficult to get a pair of bolt cutters around the lock without bleeding from the ears.
Hopefully there’s at least a brief pause before it starts wailing or getting the key into the lock will be a job best left to deaf sleight-of-hand artists.
They’re $20 a pop.
It’s Like A Car Alarm For The Rest Of Your Stuff [Toolmonger]
* Or so. There seems to be some disagreement about the true loudness.