I think there's the possibility of making human writing on a forum very easy to identify, if you highlight the text with a gradient of say light blue, the lightest being the oldest, and the darkest being the most recent. Then as the users write, you collect the diffs and have this good data for verifying that its actually a human writing this stuff.

I'm not even that strongly anti-chatbot, but I do kind of suspect we need to preserve some no-chatbot conversational spaces online, and this seems like an elegant solution.