[troutman]

Amsterdam is a bicycle theft free-for-all. No one buys nice bikes there, because they will be immediately stolen.

http://query.nytimes.com/gst/fullpag...54C0A9669C8B63

This city may well have the greatest bicycle density of any European capital, but it does not mean people won't steal yours. Bicycle theft is so common that anyone renting a bike should automatically take out insurance. Similarly, leaving property visible inside a parked car can be an invitation for trouble.

http://wikitravel.org/en/Netherlands#Bike_theft

Bike theft is a serious problem in the Netherlands, especially around train stations, and in larger cities. Never park a bike near a station, use the guarded bike parking ('stalling'). In general, use 2 locks of different kinds (for example, one chain lock and one tube lock). This is because most bike thieves specialize in a particular kind of lock, or carry equipment best suited to one kind of lock. Ideally, you should lock the bike to a lamppost or similar. Bike thieves have been known to simply pickup unattached bikes and load them into a pickup truck, so they can crack open the locks at leisure.

In cities, most bikes are stolen by drug addicts, and they sell most stolen bikes too. In fact they simply offer them for sale to passers-by, if they think no police are watching. Buying a stolen bike is itself illegal, and police do arrest buyers. If you buy for a suspiciously low price (e.g. € 10 to 20), or in a suspicious place (in general, on the street), the law presumes you "know or should have known" the bike was stolen. In other words actual ignorance of the bike's origins is no excuse.