At the moment, I can’t imagine any realistic way file-sharers can be caught. It’s possible lobby groups will try to make file-sharing count as a ‘heavy crime’, but I doubt they will have much luck.
The German criminal justice judicial system is quite overextended, and the people are overworked. Public prosecutors and judges alike were quite pissed off that they had to invest time in the many file-sharing cases, which were obviously irrelevant in a criminal law sense.
The public interest to put file sharers in prison is simply not there.