I wish that were true. The data is collected anyway by the ISPs, but not necessarily stored 6 month (sometimes longer, sometimes shorter) and not on that foundation. There were some legal proceedings because of that.
Those are different things. Just because there is no law forcing the ISPs to collect the data and providing a specific exchange interface following the EU directive, doesn't mean that germany has no other laws giving access to the data the ISPs collect anyway; and other laws permitting ISPs to collect those data. See § 113 TKG as source, which I linked below - it is not a secret.
edit: I'm trying to make that more clear. The difference is that right now, they are not forced by law to collect those data, hence the penalty and lawsuit from the EU. But they may do so - and that is done in practice -, and there is a law that if they do, law enforcement can get access.
So then, make one. Post a link to HN when it is ready to go, and promote it in Europe. But appending this question to an unrelated topic is not going to be the best way of getting it done.
Data retention law is currently ruled unconstitutional and it's not in place.