It's not the same thing at all, because the German regulations would be stopping two consenting parties from interacting with each other, while Facebook does not such thing (it just prevents some from interacting with Facebook itself).
EDIT: People assuming that I'm against all kinds of such regulations: cut that out, I never claimed that.
The 800 pound gorilla Facebook and the average German teenage girl (to name just an example) aren't exactly equal consenting parties.
The law is there to protect individual citizens against the ruthless exploitation by major corporations like Facebook.
Especially when those corporations hold the key to either social isolation or abandoning your civil rights. The laws are there to prevent companies from abusing their power from effectively undermining individual people's rights and freedoms.
I never said it can never be justified. I live in the EU and agree with most of our consumer protection laws. I'm just drawing an important distinction.
Not participating in a transaction is a personal issue, which doesn't need justification. Not letting others participate in it should need to be very well justified, at least in a State that is supposed to be democratic and just.
Personally, and in this particular case, I find the justification lacking.
EDIT: People assuming that I'm against all kinds of such regulations: cut that out, I never claimed that.