In my Twitter security post I mentioned that you should delete DMs. Ted Han pointed out to me that you can only delete them from your own inbox: the other party can still see them, and they’re consequently still available on Twitter’s infrastructure. It may still be worth deleting them, but only to prevent someone from finding them if they break into your account.

A good idea going forward, though, is not to use DMs and go to another platform. For example, Signal is a great solution for encrypted messaging.