I was thinking about this, on one hand it’s exactly what we want to avoid, on the other hand we want to enable people to connect in real life when they are travelling and it’s not easy to distinguish.
A good start, at least, would be having friendly, concise text explaining what messages are appropriate on the screen when you message someone for the first time.
We could also go down the route of confirmation dialogues etc. but there should be a balance, we don’t want to hassle all the time to remind people to be good. (Maybe the first time you send a message? Once a month?)