Actually, there was already a plan on bet limit since yesterday. But, it was delayed as we were working on speed detector and another bug fixes, it required a restart and tests.
The bet system was bugged, it give double amount of bet + additional rewards from pool. But no one reported it, probably because it's advantegous or no one realize about it( but according log, many players abused it ). Anyway, it caused alot of problems in the account system which makes it quite impposible to recover the accounts, so we had no choice other than using database from backup. A lot of cash being thrown into the server, players' account and also caused some accounts to have negative cash as it crossed the cash limit. They are all fixed now, we have also added money limit into the script itself, the limit is $800 millions cash and $800 million bank balance, i dont think anyone will reach it though..
The cash that players had won from the bet wont be returned back, we are now using yesterday's backup so your cash should be as yesterday. If you didnt bet yesterday, your cash is still there. While, for those who bet yesterday, the amount you won from bet( not including the cash you used to bet ) will be taken back from your account.