Oh, this thread was made for me.
-When someone calls The Muppets, "The Muffets." What the heck are those?
-When they refer to Beaker as "Meep."
-When someone writes Miss Piggy's name, they write, "Ms. Piggie"
-Fozzy...
-When they refer to Sal as "The Monkey"
-When they say Ernie and Bert are gay
-When they say Muppets are for babies
-When they say Sesame Street is not part of the Muppets
-When they mix up Kermit and Robin (Someone actually does that.)
-They call Fozzie, Yoda
-When they only watch Sesame Street for Elmo
I got more, but I can't think of them at the moment...