Christian Solmecke, a defense lawyer, gave a more in depth look into the system before this latest ruling. “Based on the data provided by Logistep and other P2P tracking enterprises, an offense is reported. The public prosecution service is obliged to investigate because a copyright infringement is a criminal offense in Germany.” The ISP would then be forced to reveal the identity of the alleged file sharer.
The new ruling means the media companies can no longer force ISPs to reveal alleged file sharer's identities. As was noted before, the only way to get an identity for now on will be if the file sharer is also involved in terrorism, murder, child pornography or kidnapping. I'm sure many file sharers in Germany feel a lot more safe now that this ruling has passed.