We used to be driven mad by *ing scaffolding alarms in London (scaffolding right outside our flat). Pretty much every bloody night this thing would kick off, 2 am, 3 am whatever.
One night, the police turned up, a couple in a car. Then some more turned up, then a few others a little while later. The alarm was still sounding. They looked at the scaffolding. They all drove away.
The alarm was still sounding.
HOWEVER!! -> the scaffolding was not stolen! Yay!