In the US it's obvious they aren't often needed, since (1) they were never popular for civilians to have, and (2) they have essentially been banned since 1986.

If you think there's a problem with assault rifles in the US, there are some things you need to know. One is that nobody in the US has ever been murdered by somebody using an assault rifle. Another is that a man named Josh Sugarmann chose the term “assault weapon" as a propaganda tool precisely because he knew people would make the mistake of thinking an “assault weapon" that's a rifle must be an assault rifle, which it is not.

You have been lied to by the anti-gun proponents. And if you allow people to say “X is illegal" and then change the definition of X, you've changed the country into a totalitarian police state. There's a substantial difference between a nation that cares for the rule of law and one in which people subvert the law to gain what they want.