So does this mean you won't permit it, or that you are simply warning them that they may be breaking the law?
I'm pretty sure it's a no-no on the forums.
If people are advertising it here, on Badspots forum for gambling in his game, then the risk is that he can be held responsible for permitting it.
It's not worth the risk for Badspot to get in trouble, and it's not worth the risk that someone hosting some gambling may con people out of money and those conned come back here and complain.
The intentions might be completely harmless, but it is best that it's nipped in the bud before something bad happens.
As for a general rule, if it's illegal in anyway, or is particularly shady and dubious, you should not be discussing/promoting it on the forums.