I’m hardly the first person to say life would be so much better, particularly debate and discourse, if people had to back their opinions with money (hi Kant!).
This is only a half baked idea so please trash away.
What if you built a forum that had a gambling aspect built in. To join you had to deposit a certain amount of money and then when you post you have to assign a dollar value to how secure you are in the facts and opinion in that post. Any other poster can take that bet and show your error, thereby winning the funds, or fail giving you the same funds.
You would obviously need some arbitration mechanism. I’m not sure how that would work.