I would certainly like this also.
It’s good that the Activity Stream can be viewed and edited and deleted from the Admin, but it means that the Activity Stream would have to be more-or-less constantly monitored for inappropriate comments. If we had a moderation function it could be done in batches.
I realise that it takes away some of the immediacy and instant gratification that un-moderated comments have, but sometimes (as in Norm’s case), you need censorship.