Preventative measures can be put in place
It may be worth looking into the specific safeguards implemented by Wikipedia, for example. These include first the provision of rules pertaining to content (e.g. traceability of claims to reliable external sources) which can be enforced by a community of volunteer “admins” with special editorial powers. Recent changes are flagged out as such to facilitate verification of compliance and usernames and IP addresses are logged. Users can face temporary or permanent banning.
See Hoffman & Mehra’s ‘Wikitruth Through Wikiorder’ (Emory Law Journal, Vol. 59, 2010) for review of Wikipedia’s dispute resolution process.