In order to combat tax fraud, the German government on a federal and state level cooperates with informers, mostly former bank employees, to buy facts about German taxpayers with bank accounts in foreign countries. This study explains why the informer commits an offence by getting and selling these secret facts. Based on these results the study shows that the German office-bearers involved in the "deal" made themselves liable to prosecution according to German law by buying the facts and using them for tax purposes. There is no justification for these crimes. The study comes to the conclusion that the German government itself violates criminal laws while fighting tax evasion.