A lot of people seem to forget that their own view of their own government doesn't mean the same things are true for someone else and their government.

It also doesn't mean it'll be true for their own government in the future. Violence sucks, but it isn't always bad. People should be allowed to learn these thing just for the fun of it if they want. Hopefully the time never comes where they need to be practically applied (besides the situations you gave and others like them) but if it does the knowledge will hopefully be available.