No, seriously. A naval security firm is using a “precise beam of sound” as a weapon against Somali pirate attacks. And it is hooked up to an MP3 player as a source. The idea of repelling pirates with blasts of death metal is rather wonderful, although given the advertised effects of the weapon I don’t suppose the pirates will enjoy it much:

It’s very effective up to 1,000 metres and excruciating if you get within 100 to 200 metres if it’s at full power. It would give you more or less permanent hearing damage.

Urk!