It is true that there is always a risk when playing at casinos that do not really have a long history in this market, however as long as people are prudent with their gambling then most of the time they are not going to have too much of a problem with those casinos, however the biggest risk at least when it comes to the topic at hand is to play in a casino that is relatively new but that got recent success, as that is the perfect scenario for a hacker to try to get some money as it is unlikely the security is as good as what they can find in established casinos and as such are easier to hack.
Not all new casinos are easier to hack but we can't deny that some are hacked when the casino success or starting to gain the gambler's trust. Even the old ones are hackable if the hacker finds a flaws in that casino then it will be most likely to get exploited by the hacker that will result in loss of funds or accounts of the gamblers. That's why casinos always work to make the security even more secured and find which is the reason why it got hacked and then fix it.