I could be sued for being a superhero, if i was one

Just found this article explaining that 'superhero' is a regitered trademark of both DC and Marvel comics. Bizzar. What a great question for a table/pub quiz.
It remind me of the story of the Marx brothers, when making 'A night in Casablanca', Warner Brothers tried to sue them for using the word 'Casablanca' in the film title, incase people got confused with there film 'Casablanca'. The Marx Brothers responded with threatening to sue Warner Brothers for using the word 'brothers' in there title.