What controversies have surrounded the Olympics over the years?

Well, there have been A LOT, and I mean a lot, of controversies during the Olympics. For a start, Germany was once refused entry after World War One. Also, there were all sorts of problems like women weren't allowed to enter, and also, black people weren't allowed to enter either.

Of course, there are a LOT more but I'm typing this off memory so, there are a few! :)