Tracking... How?
 

I understand how Carbonite is capable of tracking other Carbonite users through the hidden chat channel, but how is it able to track guildies? Every guild member is traced and available on my map. So are people I manually add. How does it probe for that information?

I believe guild/party/raid tracking is enabled by default in WoW.

Carbonite sends status info to guild members using the hidden addon guild channel. Your Carbonite then shows their incoming Carbonite status info, which includes position or Cartographer info if they are using that.

But it seems to be able track anyone in my guild, whether they use any addon or not. How?

It does not. There is no secret way of doing it other than what I described. I'm looking at my map and don't see my guild members who are not using Carbonite.