The link is a report of power tools being used brazenly openly in front of people, near security, in a heavy-traffic area. Whether or not someone intervened is largely irrelevant. Chances are people will not stop -- I honestly believe that from my experience in living and growing up in NY and Chicago. The bicycle owner was very lucky.

Wild fantasies? something that can happen and does happen is hardly a wild fantasy.

Of course, a properly locked bicycle will have better chances at being passed over -- duh. But that does not mean that a thief will always pass the bike over given an opportunity -- perhaps something, some knowledge and not just of monetary value makes the decision of which bicycle to steal (cycling trends, whether or not the bicycle is stock and inconspicuous vs custom and easily recognizable, new vs. old, etc).

And sometimes a bicycle is the only locked up bike for a few blocks even in dense urban areas -- if they need cash now and realize they can easily compromise the lock and make a quick $200 bucks, there is little that is going to stop them. More often than not, people will not stop them; The police have people shooting each other with handguns and assault rifles to report to and couldnt care less about a dumb stolen bicycle; and they can accomplish the attack in mere minutes and make quite an easy profit.

Hardly a wild fantasy -- come visit NY/Chicago/Philadelphia more often.