mods not allowed to add more characters to a post being edited

Hi forum staffs!

i would like to suggest for us to have system in which moderators of a forum will not be allowed to add up characters(letters,numbers,pictures,codes) when a editing a member's posts, this would contribute because:

1.If a moderator is very angry with a member(for many reasons), the moderator would be thinking to just edit one of his posts and add up a spam, porn, inappropriate messages then if another staff notices it, they will banned it for mistake

2.a members post will be always be safe from mods editing

but when a mod edits a members post, there will be 5 more remaining characters to be posted.

EDIT: i'm sorry wrong section, these should be on suggestion for your forums section.