It reminds me of when I used to work in Holland and would cycle to the train station to commute to the office.
The train stations in most large cities have HUGE bicycle-carparks, literally bikes as far as the eye could see, so people would generally get in the habit of parking in the same spots.
Anyway, I had a fairly decent bike compared to most others around i.e. I bought it new from a shop so it had yet to get beatup and was given a huge cycle lock like this.
My colleagues used to say there was little chance of the bike being stolen.
One day I came back from work and returned to my bike only to find someone had broken the padlock (and it was a tough padlock) and stole the security chain leaving the bike.
I told my colleagues the next day and they laughed saying this was not unusual, often the chains are desired more than the bikes.
I didn't know how to feel as I kinda thought it was bad my bike was not stolen, given it was a decent new bike (and worth more than the security chain). I was told there is a certain etiquette where it is ok to "borrow" old, beatup bikes (especially if it is a cold night and you need to get home and live far away) and many people do it, but taking a new bike would be "stealing", the thief however probably "needed" and nice big chain for his new bike.
I like to think there is a certain truth to that (atleast for the place and time I was there) and to this day it is one of my favourite memories of that country.
Anyway, remember having a big chain is useless without a very good lock!