While I dislike what those individuals stand for, their attitude and their ignorance, I do not think violence towards them will change things for better but rather aggravate things.
One has to look at the root of the problem. Why are they angry etc.? Fact that we have vast economic disparity within our society breeds this kind of behavior. When resources are plenty and everyone gets their fair share and doesn't need to live loan-to-loan people don't usually care about exclusion of others (well, there are always zealots with loose screws) and those movements to not gain traction. Look at fascism in last century: it has risen on the back of economic collapse of society when it became easy to accept "you can't eat because he took your food" kind of messaging.
Bottom line to stamp out those thugs we need to change our society drastically with a sharp turn left but we're keep on veering to the right with each election, which will end up in violence one way or another. Someone however has to be focused on the target though: political and economic system in Canada is broken and needs to be rebuilt, until then we will be miserable and thugs will proliferate
one caveat: I was talking about Canada where those things are not so deep-rooted