[pikzen]

Because clearly, when stealing a bike, you want the entire neighborhood hear you for ten minutes, emitting sparks everywhere, while you had to bring an angle grinder.

You're supposed to be somewhat discreet when doing that, not warning everyone.

Most people's locks can be cut with a strong set of shears. The other ones are usually not worth spending your time on unless it's everything there is. In which case, like @jacquesm said, freezing temperatures are an excellent solution. More of a middle of the night thing though. Shears work 24/7.

[tinus_hn]

I have 'stolen' my own bike after losing the key. It was in bright daylight in plain view with a ton of people walking by. No one said anything.