This is okay as long as the casino is not run legally or doing fraudulent activities that will make them wanting to be penalized for such actions. Every industry needs advertising in order to thrive and most of the time, they make use of established figures to help them run the adverts. There should be clear agreement after these celebrities have done their investigations and find out that this casinos are not illegal, but they should also mention their followers to do their own research before patronizing them. If they do so, I think this will save them from any legal suite against them in the future. This is important because you can’t trust fully how the casino can turn later after you’ve already promoted to be trustworthy ones.