It seems most common on those of the left wing who apparently cannot stand comments against their point of view. Perhaps I can be sympathetic that they are paying to publish their views, taking the trouble to run their blogs, so why should they tolerate discenting views.
I guess we expect everything to be free and easy to abuse each other with impunity, a common problem with some blogs ... a sort of fighting without blood or death ... not many wars in our neighbourhood.
I got refered to one thread on Red Alert and it was very disappointing with so many deletions and bans and hard to follow just what the thread was about. Will not go back there in a hurry.
It does seem rather juvenile all the censoring and banning.