You can't start it if you can't pedal it (unless it's a pull-start). So locking it up will prevent that pretty well.
Also, it wouldn't be hard to hot-wire one of these. I could do it without tools.
And these bikes are pretty theft-retardant. They attract on-lookers, and the more on-lookers the less likely someone will mess with it. That's what I've observed at least.
I did get a motion-detecting
bike alarm just to make someone jump if they touch it.
I worry more about people that don't mean to do harm fiddling with it, and a loud alarm will make someone that isn't stealing it stop.
