Not sure if this has been posted before or not but read in the Toronto Star that the city's famous post-and-rings can be snapped open with a two-by-four piece of wood:
Beside the post lay a plank of wood, and the metal ring that bears the words City of Toronto was left in two pieces. Lama believes there's a flaw in the bike post that allowed the thief to use the two-by-four as leverage to snap the ring in two.
"When I talked to the cops, they said a couple of other bikes were stolen that way." The officer told him to get rid of the wood "so no one sees that these posts can be busted like that."