Originally posted by supcom
You seem to assume that if the thief catches someone's attention, that someone will take action that will prevent the theft of the bike. While this is a possibility, I would think that it is unlikely. How many people will put themselves at risk simply to stop the theft of some bike? I would expect not many.
Of course there is no guarantee that someone WILL try to stop, but remember word WITNESS?
Besides, there are some people who DO take some action...