When the social interactions that it creates are little violences, then we can say that quality has fallen below the level that people will find much benefit in it. Such interactions become toxic.
Why Twitter’s Dying (And What You Can Learn From It)
umair haque

I’m an old time SM guy — and got my start on user groups for things I cared about like Windsurfing and Cars.

We had a GREAT global windsurfing community and then along came the toxic politics of the Bush v. Gore election. It infected the group, partitioned it and ultimately destroyed it.

We could survive long, heated arguments about cammed vs. non-cammed sails, but politics and the associated personal attacks killed it.