How did this person who has 1 rep comment on a question?
96392
Comment on a question without 50 reputation points
37700
How can I ask for clarification on a question I'd like to answer if I can't add comments?
27051
Why only one @user per comment?
51535
What's the justification for the commenting reputation requirement?
102748
Significantly upvoted posts, not suspended user, despite he has only 1 reputation
117715
Always allow commenting on posts I have previously commented, irrespective of current rep
38686
Zombie comments (aka wrong comments count when destroying a spammer who posted comments)
56841
Make it more obvious that commenting is only possible after earning certain reputation
48917
How to comment on somebody's clothes?
137059
Unihan characters in comments
8000
How do comments work?
20391
What happened to this user's rep, badges, and name?
138504
First Post suggests an answer from a "new user" who is 3+ years old with 1800 rep
146694
Eeeek! "Community" user got sudden rep boost.. how come?
138722
The system sees a comment that doesn't exist
61716
For protected questions, require local reputation to comment
70385
Prevent the OP commenting on their own post?