In my opinion, they should do tests before giving someone weapon license. Because there is a case like Eliot Rodger's one, I mean how can you let a mentally disturbed guy own a gun?

It's safe to say bitcoin tbh

The reason why it's hard to stop ISIS is because they aren't single military force, of course they can bomb their headquarters but that won't get them anywhere. What I mean by that is you can see the suicide bombers and stuff, let's put it like this, there is at least one suicide bomber in 10.000 people(for example), therefore it's really hard to track them down or get rid of them all at the same time, hence why ISIS can't disappear overnight, and they need them for oil too so yeah.