I changed my mind about online community this year.
I still believe that there is no fully automated system capable of managing the complexities of online human interaction — no software fix I know of. But I'd underestimated the power of dedicated human attention.
Plucking one early weed from a bed of germinating seeds changes everything. Small actions by focused participants change the tone of the whole. It is possible to maintain big healthy gardens online. The solution isn't cheap, or easy, or hands-free. Few things of value are.