Recently I have been seeing a lot of destructive behaviors on LeetCode Discussion sections. I started doing LeetCode challenges (April and May) and whenever I have solved a problem, I painstakingly take time to write up a discussion post (along with step-by-step thinking processes and visualizations). Lately, I started to find out that the votes in my posts become zero after I have got something like 4 or 5. Then one of the commenters commented on my post asking why his comment has been downvoted. I realize that not only that person's comment has been downvoted, all the other comments have been downvoted as well. Something is not right!

I did my investigative work with one of the problems in the May LeetCode Challenge. After realizing that someone has completely downvoted my post to 0 (along with all the comments in my post), I started to observe "some users" getting to the top of the "Hot" section very quickly. Another supporting fact is that not only my post and comments get downvoted, all the other posts in the "Hot" section are all downvoted to zero for that problem. The quality of the answer from "that user" who is supposedly at the top with most likes in the "Hot" section is very questionable (no explanations and likely copied from somewhere). I later found out that creating multiple fake accounts on LeetCode is very easy and a miscreant can just create multiple accounts with throwaway temporary emails and upvote his/her post while destroying others' posts. Given access to user session records, detecting this kind of user pattern can easily be replicated with rudimentary data analysis work.

I wish that I can get this noticed by LeetCode team. They can filter out anomalous user activities by looking for users performing multiple downvotes within a short period. Heck, if they need, they can check whether multiple users are performing multiple downvotes from the same IP address. There are potentially many ways that a miscreant can fly under the radar by renewing their IP and potentially hop various IPs with VPN. But still, the least LeetCode can do is limit the number of consecutive downvotes from a single user session.

The only reason I am raising this concern is these types of destructive behaviors can destroy the morale of newcomers to this otherwise great community. The best way to learn coding is by sharing your approach and making sure that you can articulate your thoughts in posts. This not only helps the community as a whole, this helps the author with his/her thinking processes. I truly wish some action will be taken.