Whenever a new user does an action it creates two transactions, one to fund the account from the faucet and another to do the action and return the change.
Tipping and sending are not allowed unless an account is funded, but other actions are free as long as there is money in the faucet.
Thanks for the feedback. It does have a limit in place. I think it would be hard to steal from the fund via double-spend, but would be interested to see if it's possible.
Yeah, it is hard to steal via double-spend, especially when avalanche being actived. Cheaters may steal fund by miner bribe double spend attacking if there exist dishonest miners.