Vispilio tried to troll but in the "real life", if you pull "yeah, it is pyramid scam" and you still decide to advertise it, and you get caught, you will be fined. For example, in my country, if you knowingly advertise financial pyramid scam, which is what you agreed to advertise when you took that signature and said they run pyramid scam, you can get up to 3 years in jail.

Gambling and all "investments" that are so risky they might as well be gambling (HYIPs, pyramid schemes, etc.)

Games where the main factor is whether or not new "investors" join the game. Also any Bitcoin-denominated investment product with an APY far above the reasonable market rate.