I don’t see that as a problem. On the other hand it must be noted that while the chats are encrypted the metadata is open to see. Anyone logging with your public key can see that you’ve sent private messages to person B. They can’t see the contents but they know you’ve contacted that person and apparently most of the times is enough to incriminate you. I’m sure there are people working on making chats more private but as of now please refrain from wrong activities on nostr private messages!