Islam is not a race, but the fact that there are so many people that confuse Sikh people, or any brown people as Muslim in the U.S. means that there is some crossover in a lot of people's mind between "middle easterner" and "Muslim." - and yet we never hear about a potential 'backlash' from the Sikh community, at least we don't in the UK.
Obviously, calling people 'towelheads' is wrong. Obviously, calling all Muslims 'terrorists' is wrong. Both these bigoted opinions should be called out. There should be no place for these bigoted opinions in public/professional life.
And yes, white Christian terrorists are very dangerous and should be stopped, with lethal weapons where necessary. Maybe in the US, white Christian f**ktards present a greater threat than Islamic extremist f**ktards.
But I think the picture is different if looked at globally. Monsters like Anders Breivik are few and far between, thank goodness. Plus, there are no white Christian extremist groups currently carving out territory in Northern Europe and massacring minorities whom they hate.