Is multiple account allowed in this site? I think that this can be abuse easily. I can create two account with two browser and claim two block / 1 minutes. Not saying im doing this but this is just a possibility that someone maybe doing this right now
It is possible, to anyone who does that, there might be a surprise sooner or later.
what can you do about it? i mean you can ban the accounts but doing something more is impossible
It happens at all the casinos, this is why some of the dice sites have a very minimum faucet and it gets increased when a player has wagered a certain amount, and that is how they differentiate between real players and faucet players.
OP if you feel that it's being abused, you can make restrictions such as faucet winnings cannot be withdrawn and must be played at any board at-least once. If they win something from that they are free to withdraw.