The Irish singer had one massive hit in 1989 thanks to a song that Prince wrote for his very own band but never used titled “Nothing Compares 2 U”. But as big as that song was, most people seem to remember Sinéad for the reason she was banned from ever appearing on Saturday Night Live ever again. Why was this? Well, she performed Bob Marley's “War” and, right before the song was over, she grabbed a picture of the then Pope, John Paul II, and teared it up while telling the audience to fight the real enemy. Rage Against The Machine Many rock bands are known for being controversial and for sharing their ideas with the world in politically incorrect ways. When Rage Against The Machine appeared on the show to perform back in 1996, they decided to hang American flags upside down from their instruments. The crew from SNL quickly ran to the stage to remove both the flags and the band which never appeared on the show again. Martin Lawrence Being a comedian sometimes means you have to say things that could be shocking in order to make an audience laugh and it looks like that is what Martin decided to do on SNL. The comedian decided to talk about 90s women and about the decline in their personal hygiene. That didn't go down well neither with the audience nor with the producers who decided to ban him from the show. Adrien Brody Actors are known for being good at improvising, but the producers of the show hated it when Adrien decided to do so and introduced the hugely popular Jamaican singer Sean Paul wearing dreadlocks on his hair and donning an awful Jamaican accent. Steven Seagal Acting like a diva isn't nice, and that is what Steven did while rehearsing for the episode of SNL he was meant to host. That was reason enough to ban him from the show.