Restrict comment editing

restrict-comment-editing.php

<?php

// http://scribu.net/wordpress/prevent-blog-authors-from-editing-comments.html
function restrict_comment_editing( $caps, $cap, $user_id, $args ) {
	if ( 'edit_comment' == $cap ) {
		$comment = get_comment( $args[0] );
  
		if ( $comment->user_id != $user_id )
			$caps[] = 'moderate_comments';
	}
  
	return $caps;
}
add_filter( 'map_meta_cap', 'restrict_comment_editing', 10, 4 );