Responses
I hope they adress it in the next chapters of the manga, but in the novel it gives a sort of explanation I thought was pretty good.
Basicallly.... (SPOILERS)
What it came down to is a sort of: This is not real so whatever I do here, whatever I am or whatever crimes I commit are also not real.
While I do think the whole summoning business needs to be banned completely - those kids that did this grew up in an age where they know what terrorism is.
Whatever excuse they make for themselves (jealously, spite) they are the furthest things from heroes. They've become terrorists.