Well, I'm assuming it works like Stack Overflow. I can edit my own posts, but not those of others. Only high reputation moderators have the ability to edit other people's posts.

Here's how we coach moderators on the internal Stack-like site we run...

Editing

When editing content written by others, do so with respect to the person who is the original author of the content. Correct simple spelling and grammatical errors, but don't rewrite whole sentences or restructure some else's document. Instead, post a comment suggesting changes or corrections.