It bugs me when unregistered users edit my Answers. It's not that big a deal to undo their edits (Moderators always seem to approve them almost immediately), but when they make really bad edits (and they always do) I can't communicate with them why their edts are lame.
I agree that not being able to communicate with anonymous users is an issue, because there's no way you can tell them what is/is not wrong.
The following edit suggestion is a good example: https://superuser.com/review/suggested-edits/53965
I should be adding another solution instead of editing someone else's solution, but I didn't know how to do that.
The suggestion is incorrect, because it's an "attempt to reply to or comment on the existing post", and I have no way of telling the person what to do instead.
What I'm suggesting is:
- Require more attention from the reviewer when handling suggestions from anonymous users.
- Inform the anonymous users that they should register when making substantial changes/additions.
- Or, limit anonymous users' capabilities for making substantial changes/additions.