She went by the name Mildred Gillars but most G.I.'s knew her as "Axis Sally". She was an American Broadway actress with limited success, who drifted over to Europe during the 30's looking for fame and fortune but instead got involved in Hitler's propaganda machine when war broke out. With her sultry seductive voice, she was soon nicknamed "Axis Sally" by Allied troops, while playing records, along with her pro-German tripe about leaving sweethearts back home and giving up the fight. But after the war she was caught among the ruins of Berlin in March, 1946 and flown back to the States and charged with several counts of treason. Like Lord Haw-Haw, Tokyo Rose and other broadcast traitors, who claimed they were coerced and were simply used by the enemy for propaganda purposes...yeah sure. She was sentenced in 1949 to 10-30 years in prison and finally released in 1961, afterwards she became a school teacher. She died in 1988 at the age of 87. Last I heard there is movie about her life to be hopefully released this year staring Al Pacino...sounds interesting. Guilty of treason! The One and Only "Axis Sally" - Crime Capsule
With cases like these, it's hard to measure how much actual or potential damage may be imputed on the accused. So you can't decide if the punishment was for that, or the sheer hatred for treason.