Users who accumulate sufficient karma gain the ability to "flag" a post. When a sufficient number of different users with "flag" power click "flag" on a post,

Users who accumulate sufficient karma gain the ability to "flag" a post. When a sufficient number of different users with "flag" power click "flag" on a post, then it becomes [flagged]. More description here: https://news.ycombinator.com/item?id=12173809 https://news.ycombinator.com/item?id=12173809