Why would anybody get upset by the drawn image of the prophet Mohammad?

[Gandalf]

What a surprise more muslim rubbish all they seem to do is cause trouble! EDL!

I don't think most Muslim's do cause the trouble though. I really think most of them sit quiet, thinking a lot like us, and would just wish that everyone else would just lighten up about the whole thing. It's probably less easy for them as they are living around a lot more active and scary individuals.