First of all, it should be considered that this is a toxic member base that creates a toxic community environment. Once your community is toxic, it is a hard job to recover it. You may need to turn the members around and make them positive, raze it all to the ground and start again, or close community entirely.
When a community gets toxic, the first thing that the community management team does is spending a lot of time on cleaning the unqualified contents and users. But as soon as the community is left more to itself again, it goes back to being a toxic environment. So the community managers need to stay involved and active within the community to keep it running smoothly.
One of the most famous examples of a toxic community is Digg. Not many years ago, Digg was the future of content and online community. But even the site's founders and formers barely uses Digg anymore. It is surprising to know that the most important conversations about Digg are taking place on other forums and social media.
Now the question is how this happened? How a community’s environment become unpleasant for the experts and valuable users?
In Digg’s case, the very undemocratic atmosphere was a problem. Anybody could submit a story then anyone else could vote it up or down. But the problem was that anyone with a lot of friends could message his/her friends, asking them to vote up the story to have those stories hit the front page. Being on the first page was all the users wanted.
When ordinary users, with not many friends, were posting a very important content, they could not get enough vote-ups to get to the front page. The only way for a story to be recognized was to be duplicated by one of the super users with a lot of friends. Super users were always on the front page, getting more and more connections, and staying on the front page forever. This cycle continued and became a big headache for Digg’s community moderators. So the majority locked out of meaningful participation; Digg became very undemocratic at this point.
To solve this problem, community managers made it inactive for the users to message their friends, and instead, they outsourced social media. They made it possible to integrate with Twitter and Facebook, and this was the second mistake.
Of course, this is important to have integration with other systems, but too much outsourcing can put your community somewhere between and make it not very recognizable.
Besides, categorization is something vital for any online community. A community is all about content, and content needs to be categorized. If you don't segment a group into smaller groups, a community will cease to be a community at all. Having different topics in your community, and keeping the balance in generating content for each topic is a must to have a successful online community.
In Digg, some topics like “Technology” were very dominant and even had so many sub-topics, while, other categories like “Art” or “History” had not a place. In a healthy community, content categories should be diverse and more general and have the same amount of importance.
Moreover, never forget that users and content generators are the most valuable assets of a community. As bloggers are the main content generators on the internet, it is necessary for an online community to allow blog posts and let the users decide if they're "weighty" enough.
Also, always be welcoming to different opinions and let users challenge a content. Seek for the idea sharing, not for a theoretically correct answer. At the end of the day, this is the shared experience that makes the difference, not the correct answer.