This is going to be a central question to whatever the law turns out to be. If you post to a group forum of any sort under your real name and a member of the group shares your comments outside the group, is that actually doxxing?

How big is a chat before you can reasonably/legally argue it isn’t private?

I don’t have the answer to these questions. Personally, I would never assume anything I said in a group chat with 10+ participants would be private. In the cited example, where we have a group of 100+ people, I can’t see how that could ever be argued as private communication. If some of them are posting under their real names, I can’t see how they can claim someone else leaked their identity.

But, I’m not writing the law. It will be interesting to see what the government proposes.

Originally it was when someone with an online persona (pretty much everyone before Facebook and the garbage internet we have today) had their real life identity revealed. Now people call it doxing when someones home address is revealed. In a lot of countries this is public information. Not a big deal really.