One of my co-workers got himself a bike and told all of us that he was going to start biking to work instead of driving. But, three days later, it was stolen from in front of his apartment.
The problem is, and there's plenty of evidence on this, an equipped thief can breach just about any lock out there in a few minutes and generally nobody will stop them and ask them what the hell they are doing taking a battery powered dremel to a piece of bike lock. This includes both U-locks and chain locks.
There's a huge market in used bike parts and most of them don't have serial numbers. Metal bike frames have a scrap metal value. So, a thief can sell the bike piecemeal, or they can try and sell it whole. I was talking about this on the train and one of the riders claimed that a person they knew was always stealing bikes, riding them until something stopped working, and then abandoning them and stealing another one.
There's no bike licensing or other routine sort of transfer-of-title process that would reveal that the stamped serial numbers of a bike were either scraped out, tampered with, or reported as stolen.
And when there's a question of priorities, you can bet that police are not viewing reducing bike theft as a priority. I'm not even sure if there are cheap and easy answers there. There's only so much you can do with portable locks. I don't think that required bike licenses are the greatest of ideas. Active security requires power. I'm not even convinced that a communal bike storage area is such a hot idea, given that we had a thief in a fairly foofy apartment building that stole my bike, my GPS, and broke into my upstairs storage unit.
I tend to think that most correct answers involve real amounts of money and architecture. Things like valet bike parking and individual bike lockers, or the ability for cyclists to take their bike with them.
The co-worker still hasn't replaced the bike. If it lasts a year or two before getting stolen, that's one thing. You can amortize that. But after 3 days, unless you want to denote space inside your apartment for the bike....