Normally nothing good comes easier so if someone is promising you that you should invest or bring a certain amount of your coins for him to get it doubled for you is simply crazy and funny because a normal person even without been told will know is just a cheap scam. Greed is the only thing that can make any folks fall for that cheap scam,

Just like the OP said they have there kind of terms (language been use) that always sounds hastefully, once that is senses or noticed run or you have your self to blame.