"Coming together" is a bit difficult to determine -- how do you identify a large group of recipient addresses as a single entity? How do you differentiate between a group of addresses belonging to a single owner, and a group of addresses belonging to multiple owners?

We can construct a graph tree all destinations beginning from that one address, but what good would that be? Where do you make inferences to determine the identity of the recipients? How do you group them together?

At some point your trail becomes so long and so disparate that any effort to continue following that trail would be a pointless endeavor.

Sure the technology is there to follow the trail indefinitely, and (where available) you can easily check all recipient addresses from this "poisoned" tree against regular fiat exchange logs, but within the BTC ecosystem? It's an interesting intellectual challenge, but not useful.