Removing prohibited material such as comments by banned users, libel, legal threats, personal details, or violations of copyright, living persons, or anti-promotional policies Removing harmful posts, including personal attacks, trolling, and vandalism. This generally does not extend to messages that are merely uncivil; deletions of simple invective are controversial. Posts that may be considered disruptive in various ways are another borderline case and are usually best left as-is or archived.