Stolen bikes

Entrapment is what you're talking about, however if the person is ready and willing to break the law.

With that bike locked on just the seatpost, it's likely to be called an entrapment as it lure people who wouldn't otherwise steal bicycle to have a go (as other have said - opportunity thieves).

it's a bit of a fine line at time, is there's really a difference between a normal regular thieves and those who decided to steal because the opportunity present itself?

Thanks Rumpole.