We realized that now users can remove themselves from private messages.
This feature has an unexpected consequence. I found out that a few users in our forum are sending private messages sharing some WeChat Group QR code which is against our forum policy, but they are really smart. They always remove themselves from the private messages after they are done, then the private message history is gone. Therefore I as a mod can’t see what they have discussed by viewing their profile any more. This significantly limits the mod’s ability to execute the forum policy. Please fix this!
That does make sense now from what I have observed. It would probably be fine for the use-case above (@physixfan, have you worked out some SQL yet?) as is, but yes it would be an improvement if there was a nice little record of those who are removed from the PM.