A few points
1: If they'd have just executed the guy they'd have created a martyr - that's politics 101 - to the point even David Cameron could grasp it...
2: Whether you care to admit it or not, credit where credit is due, Breivik has proven to be a tactician of the scale of a Von Manstein, Allenbrooke, or Blucher - if he'd have been in an army in wartime he'd be parading round the place with a Dannebrog, a GCMG and at the least a Ritterkreuz mit Eichenlaub & Schwerten... FOR DOING EXACTLY THE SAME DAMN THING.
3: Drone Strikes - aka bobbing for brides/whack a wedding... and don't you dare tell me they're legitimate targets if Russian partisans weren't. Oh silly me - if I'm a private citizen & kill 80 odd people that's a crime - if I'm a police officer, a soldier or a politician -they'll give me a goddamn medal..
4: Contrary to popular belief its in the authorities best interests to keep this unpleasant individual happy - happy sociopaths are quiet sociopaths - and having the world media barf out the whole situation and the embarrassing incompetence of the security forces is not helpful - nor does it help the victims survivors/families.
If your pet sociopath wants his games, especially if he's an anti-darling of the media, you'd best swallow your revulsion & pony up, if only to shut the guy up. In this case all publicity is bad publicity.
5: I find it pretty telling that in Europe when this sort of thing happens gun control is tightened up before they've found all the bodies - in the US they debate Uzi's for schoolkids.. god I love the American Dream..
Finally - for *insert deity here*'s sake - actually sit down and look at your society critically just for once. Do that and hopefully you'll begin to understand why people like Breivik pop up. Modern society in alot of senses makes life in the dark ages positively dreamy by comparison.
I don't condone what this individual did but then I'm sure I'm not the only one who's contemplated the improvement garnered by the British economy if someone had emptied a Sten into a certain Mr Osbourne a few years back. Its an unpleasant truth that should be stated - the only difference between Anders Breivik and the majority of the rest of humanity - he did what many of us contemplate daily..
Don't you just love civilized society?