"Hitler considered anti-Nazi humor an act of treason, and from 1942 to 1944, the infamous People’s Court of Berlin issued 4,933 death sentences, many of which were linked to “defeatist” jokes. Herzog argues, however, that it wasn’t as dangerous to make fun of Nazis as some have claimed, and that most people executed for being funny were targeted for other reasons. If anything, he says, Nazi jokes helped to keep the regime in power, allowing ordinary Germans to blow off steam."

Source: http://www.vanityfair.com/culture/2011/06/whats-so-funny-about-the-nazis-rudolph-herzog