So they lose credibility and are Balkanised.
And then there is Bruceongames. This site started with an open comments policy but started receiving so much vitriolic abuse from ignorant fanboys that now every comment is held until it is approved, which can be for days when I am travelling. Not only that, I send the abusive comments to Akismet, something the fanboys probably don’t know about. And Akismet progressively closes down that person’s rights on the interweb. So they are less able to be a nusiance in future. But which also means further Balkanisation.
I also run a great forum for artists, it is a friendly and supportive community for practicing artists. Yet a full 50% of people who join do so with a narrow agenda of promoting their goods or services and are mostly not even artists. This, obviously, is very damaging to the community. So I have been forced to make the rules stricter and to implement them more thoroughly in order to protect this great community. And once again it Balkanises the interweb a little more.
So every time the interweb is abused it leads to a reaction to prevent future abuse. Which means putting limits and restrictions down. The fanboys damage themselves because what they can get out of the interweb is being continuously throttled as a reaction to their stupidity.
This makes life very difficult for the online marketeer. Blogs and forums will be attacked by idiots which means that they need stricter rules and policing which reduces their quality and usefulness. Community liaison continually come up against agressive fanboys with a narrow agenda shouting down anything they don’t agree with. It is a changing reality that makes things a lot less Web 2.0 and a lot more like the we talk you listen days of old.