We want to encourage users to write more private messages about contentious or personal feedback on posts (and do it in a civil and friendly way…), rather than posting it public and possibly steering the conversation off-topic. Here’s the badge:
SELECT p.user_id, current_timestamp AS granted_at FROM posts AS p JOIN topics t on t.id = p.topic_id WHERE t.archetype = 'private_message' AND t.title LIKE 'Your post in "%"' AND p.post_number = 1 AND p.like_count >= 1 AND (:backfill OR p.user_id IN (:user_ids)) GROUP BY p.user_id HAVING count(*) >=1
I didn’t find a specific trigger for flag messages, so the query uses the default title “Your post in …”. I’d say the badge is easy to game or cheat in several ways, but it would still achieve it’s goal just by giving more visiblity to this feature and communicating that this is regarded positive action for the community.