Well it's 3:55am on a saturday atm in Germany so I doubt any german beside me is going to answer.
Bundesprüfstelle für Jugendgefährdende Medien = Agency to protect minors from viewing baaad stuff
They are going to ban your site
They write that you have to send them a statement within one week after you got the letter if you got any
objections against this.
They write how baaad your site is and why they are going to ban it (showing hardcore ouside member areas/avs systems is illegal in germany).
Could you please write them a letter and tell them to fuck off and not wasting tax payers money.You are living in the US and they can't do shit,they've gone crazy lately.Also tell them that they should write fucking english if they write letters to foreign webmasters who ain't in any way under their juristriction.
Hope that helped you.