A friend of mine lost his key chain; again. Its nothing simple to lose keys in Germany. Keys are very difficult and costy to get copied; and worst, each copy has to be registered somewhere with the government. So first he paid to get the lock of his room changed (that's mostly the solution). Then he was directed to check regularly an office in the city where people give items they find on road etc. His keys were not found. The key ring also contained the key to his room in university. So may be they changed that lock as well.
The university also gives a special "transponder" to researchers which is used to unlock doors of the building which contains your room. This way, they can enter their labs or rooms at night or on holidays. This is a blue-tooth device which sends signal to the electronic door lock on every building. Each building has a different lock and hence different transponder. They told my friend that changing of these locks of one building costed them hundreds of euros, though they didn't charge him. He was shocked when he lost the keys the second time, but thanked God when he found them. The first keys are still nowhere to be found.