This is kind of a depressing one. Just popped in there though when you mentioned Christmas carols.

Out on the bike rack bike thieves pause,
Spies a nice frame and uses steel jaws,
Pulling off bike chains, and riding away,
Spoiling a christmas holiday.

Ho ho ho, Who wouldn't know,
Ho ho ho, who wouldn't go,
out in the cold to catch bike thief,
it's beneath the job of the busy police.

First goes the lightspeed of little Diddley,
Then goes jonathons brand new riddley,
Locked with a U-Lock but victim of pen,
Bicycles stolen again and again.

Chorus.