If it's illegal then I don't think they just tell it out loud to every user.
There could be handpicked groups they are attacking to prevent from being exposed.
I think unless you bumped into them you won't really notice something like that is happening.
You are right. I was also contacted by a person who wanted to know if I belong to a place where gambling is not legal, and when I said 'yes' to know more, he started asking me if I want to use him to bet on my behalf on bookies he knows about and will get me better odds than I can get on normal online gambling portals. I refused to get ahead with it because of the risks as we should not trust anybody of even $1, and he was asking me to open an account with minimum $500.