In Norway there are actually no restrictions on moderators, unbelievable as it may seem. And almost everyone has one or several now, and we have not seen any increase in criminal activity with either guns or guns with moderator, so I can see no reason at all that they should not be allowed. It takes away the worst noise of the shot and you get a reduced recoil as well, a win win situation.

The only negative sides I can see with a moderator are that it looks really bad, especially when someone ruin a classic rifle putting a moderator on it, and that you have to remove the front sights to mount it.