The Economies of Bike Theft
From an American website but answers some questions you didnt know you had.
The scallies round here tend to use them as transport. They just ride them into the ground and then just nick another one. Maintenance is low on their list of priorities.
Sometimes the younger ones come to me if there is something wrong that needs fixing - i moan at them that they should look after their bikes better but look at me like im mad.
They obviously dont bother locking their bikes up - ive even known them to ride a bike somewhere and just leave it - knowing they will just nick another one when they need one. I even think they nick them off each other as and when.