We’ve had growing social and legal concerns, both internally and externally, that moderation for Direct Messages (DMs) is needed. However, the heavy privacy implications of what having to moderate DMs actually entails are a lot for us to have to manage ourselves.

We can’t just look through people’s messages, nor do we want to. Should things change, the feature may return at some future date; however, it is not in our roadmap.

(repeated verbatim from https://preten.do/dms-sunset which says that better than I can)