Everything that is out in the open here will (if it's worth) be (ab)used to make money. That's life. I can understand your concern and I've been in the same situation - even seen my own deals being sold on a paid-for mailing list.
Lots of activity has been moved to private forums and mailing lists to counter this.
It certainly doesn't solve the problem but merely creates yet another myriad of issues: whom to allow in, whom to throw out, how to identify potential leaks ...
One thing to also consider is that there are multiple forums and there is a good change that several people found the same deal - completely independent.
I'd say you could find lots of deals by merely checking the Kayak explore maps and never visiting FT (btw: this means that somebody already search for and found the specific deal).