Description:
Does it bug you that you have to register your identity when you buy a pre-paid mobile phone card?
Germany's anti-data-retention initiative provides you with a pre-paid SIM card for mobile phones that is registered on another person - if you provide your own pre-paid SIM to them. Here is a web page describing the rules for the pre-paid exchange:
http://www.vorratsdatenspeicherung.de/content/view/187/77/
Note that this is all in German language yet.
Happy SIM card trading!