I'm not trying to be a dick, but I fear I'm beginning to sound like one.
A million people standing silently in the street will never stop a lunatic intent on carnage or prevent a lunatic from doing something he feels compelled and motivated to do. They might slow him down, since it would take him a while to get through all that. But they wouldn't stop him. They (in Egypt and Tunisia) will not ever stop empty-headed radicalism either. Not in a million years with a million marches or sit-ins. Never.
As for adults having guns on the island - all I can say is I would have been petrified if no adults had guns in some of the remote places we camped as a kid in northern Minnesota. Not to shoot lunatics with, but for emergency protection against large (and very, very large - like, bear large) wildlife.
I don't know what the hell was on that Norwegian island. Maybe there was no reason for anyone to have so much as a sharp stick. What do I know? It's all theoretical anyway since I wasn't proposing a solution, just putting my random thought out there. I was not, and am not, suggesting that everyone carry guns around to pick off nut cases when they come unhinged.
But I do carry a very sharp knife in my pocket, and if by some strange twist of fate I found myself behind someone who was indiscriminately shooting people, I'd pull it out and stick it in his fucking neck as hard and as deep as I could. Yes, in a savage attempt to kill him! Because a violent action like that is the only way to stop someone who is doing something utterly insane like randomly shooting people.
If someone had taken the Norwegian shooter out - in a violent fashion - everyone on earth would be hailing them as a hero. They'd give them a fucking medal, they wouldn't get all angsty about whether what they did was moral or polite or civilized. That's all I'm saying. You can't fight fire with hugs or daisies or "more democracy." The world and its people often suck, and sometimes you have to get your hands dirty to keep things on the level. That's all.
And that's more enough from me, I'm sure.