East German spies are not necessarily more criminal than their West German colleagues. They just happen to have worked for opposite sides.
That, in a nutshell, was the judgment yesterday of Germany's highest court - which will have considerable implications across the country.
Markus Wolf, former head of the HVA - the foreign espionage arm of the Stasi - was sentenced in December 1993 to six years in jail and that sentence will now have to be overturned. Mr Wolf has been on bail since 1993, pending appeal. Hundreds of other East German spies are thought to be affected.
Mr Wolf had always made clear that he believed his was a political show trial. Critics of the trial compared his fate with that of Klaus Kinkel, his former opposite number in the West. In the words of one placard outside the Dusseldorf court in 1993: "Wolf, sentenced - Kinkel, [German] foreign minister."
Yesterday's judgment pointed out that spying cannot be seen as an ordinary crime, which is judged by the same yardstick everywhere based on a "shared social and ethical set of values". Rather, the court noted: "Every state only threatens to prosecute espionage on behalf of a foreign power - while it continues to carry out espionage itself, and protects its own spies."
The court also noted that there was an obvious asymmetry if East German citizens "without taking any action" suddenly became citizens of the Federal Republic of Germany and then found themselves prosecuted for carrying out what would have been "a legal and protected activity under East German law". The judges believed that it was wrong for "the Federal Republic, which is now also their state, to continue to behave as a foreign power".
In most circumstances alleged offences carried out before German unity, in 1990, can in any case only be prosecuted if an offence was also committed under East German law. This is to avoid a "moving-the-goalposts" form of justice, where legal actions can retrospectively be deemed illegal.
There continue to be grey areas. But East German spies who worked only from East Germany are clearly protected.
The judges said East German spies who were active in West Germany should be given "lenient treatment" - because West German law was broken, but East German law was not. West German citizens, on the other hand, can be prosecuted.
Yesterday's ruling was not unanimous. Three judges issued a dissenting opinion, which argued that the ruling amounted to an amnesty.
The dissenting judges pointed out that the first and last freely elected East German parliament had argued against granting amnesties in 1990.
There has been a widespread belief in Germany that the little fish are prosecuted, while the big fish are allowed to get away.