In Yoomoot, only 'trusted users' can edit other people's comments (even then only if the comment-creator has given trusted users permission). Trusted users are people we can trust to follow Yoomoot's guidelines.
When it proves necessary, these guidelines will be fleshed-out to stipulate that users shouldn't edit other people's posts, beyond simple spelling and grammar corrections, unless they agree with the point of view expressed in that post. Therefore editing should always strengthen the post, for example by adding additional evidence.