Why do anti-Catholics keep insisting Pope Benedict XVI was a Nazi?

The Pope was born in 1927. He would have been 6 years old, when Adolf Hitler came to power. He would have been 12, at the start of WWII. His parents opposed Nazism. All German children were required to join the Hitler Youth. He was conscripted into the German Army and later went AWOL. This claim that he was a Nazi is very unfair and offensive!