There has been a rash of disappearing bikes in the burbs up here too.
Thieves around here are lifting the bikes onto skateboards and rolling them off to a location where they can do some heavy lifting without anyone noticing.
Just cause you lock your steering column and maybe even put a lock on the rotor so that the wheels can't spin doesn't mean they won't be able to wheel them off anymore.
I've used the skateboard trick to move everything from a hot tub to refrigerators. Never occurred to me that someone might steal a bike that way.
Bad guys have gotten smart. We need to get smarter.