You mentioned Facebook ... Congratulations to the Globe
and Mail for not succumbing to Facebook blandishments.

Facebook has become the universal gatekeeper screening out 
those whose posts offend the established narrative ... Thus 
limiting access to newspapers comment threads.

Facebook is Big Brother name nowadays.

Still, that said Discus is best. 

 With Discus there is open communication between 
correspondents. So some people post nasty invective 
and slander. These are our neighbours too.

We are all adults here! So some are repetitively offensive.

Experienced commentators learn whom to ignore. 

As far as editing. One caveat with respect to written posts.

Limit comments which are repeated more than twice on any 
one topic. That apart let people have their say.

I have sought to cancel my Facebook account but that 
seems impossible. Facebook is de facto Fascist.