Are the majority of Muslims...?

Like they are in the media (crazy extremists willing to kill for their beliefs)? Or is that just a negative stereotype? I'm not trying to offend anyone, I'm just a bit worried because someone in my life recently made a remark that Islam is taking over the world. I typed that into google and some people agree. This has me a little worried. Will they take over the world? And if they succeed, will they go all dictatorship on the world? I worry a lot.