Users who created the resource (wiki page, document, blog, etc) are given all permission rights for comments causing an awkward permission situation.
Example: Regular user, Bob, posts a wiki article. Boss user, John, suggests changes via comments. Because Bob created the wiki, he has all permissions for the comments on his wiki page. Bob can then change John's comment to say "Excellent work Bob! We're giving you a 100% raise and my Boss position."