Why can't they be anonymous? They don't seem to have done anything to anyone. In fact, it's the other way around. They obviously feel victimized and are now being told their concerns have no merit.
I agree that it is cowardly and fuckin useless for people to threaten behind anon. It makes them brave. But there have been no threats here, only the voice of opinion. To say they're wrong because they might be people who have threatened us once before is hypocritical.
Why talk to anyone in this building ever again when they might be someone who groped us in the dark or put something under our door?