Reading about Fonic, it says
Activation:
The card must be activated online
FONIC -- Das ist die Wahrheit. (then "SIM freischalten") or Tel. 0800-4636642, Mon - Sat 8 - 20 h. You need a german bank account, a german address and a passport-number. For the first activation you must recharge 10 Euros from the german bank account
so not good for US citizens, no?