Aside from being caught and freeze all the account. I think it’s useless because casino welcome bonus often have a high wagering requirements which is extremely hard to complete.
You can add the max win on the bonus set by some casino as extra hurdle to avoid being abused the bonus by multiple account users.
Casino is prepared on worst case scenario.
Exactly, play reasonably, deposit reasonably, and don't target bonuses for us to use, it will become better options for us to stay playing with save. Because, if we are not a gambler with a lot of money, there's no reason in chasing these bonuses. We might feel this is unfair, but almost all bonus models come with "terms and conditions." If we feel can't meet the TnC, just let it go. Even if we are losing that bonuses, it's not a loss for us.
Chasing a welcome bonus is like chasing a train that has already gone a long way because the wagering requirements are so high, usually more than 35x or 40x wagered.
So while playing the casino itself never chase bonuses because you already know it will be difficult to get even though the welcome bonus is tempting ... like the first deposit 100% - 200% and so on this is just a casino marketing trick so that they continue to play.