I see... so the key indicator is when their activity matches their post count? I noticed that happens sometimes and took a moment to figure out how it was possible, but at the time I put it down to coincidence. I know what to look for now, thanks!
It is not quite that simple.
https://bitcointalk.org/index.php?topic=1591598.0 Gives a better, slightly confusing, methodology to finding them.
I will try to publish clearer information here now I'm up to speed!