I think that if User A "replies" to User B, you then allow anyone who can see either party to see both parties, at least in that one conversation. To detect re

I think that if User A "replies" to User B, you then allow anyone who can see either party to see both parties, at least in that one conversation. To detect replies, one option is to do a statistical analysis of the typical time between two messages on the network. Anyone who replies in the upper 70% percentile is "replying" You could make the effect fuzzy and have a back and forth conversation (which would probably be obvious in the data) have a stronger effect and could use that for training your algorithm.