Is it illegal to give away money to followers?

What if I said I would give 1 ETH to a randomly chosen follower this Friday? 

Screw it, let's do it. I'm gonna give someone 1 ETH on Friday. 

Only rule: Must Recast this post with what you'd do with the ETH

Not sure, but one option in my mind would be to create an agent that really works and give it this as collateral, collect all the wallets from the people here who really need it and let the winnings be distributed as a passive income to everybody. If someone else is already doing this successful, I would like to hear from them, how ✌️.