People must be responsible to keep their very important and sensitive documents like identity documents safely. If they lost those documents to hackers, it's their responsibility by having bad security practice on their own devices. If they did KYC on one or some platforms, their identity documents can be leaked, sold or whatever by those platforms and they can not control it, though they must think of why they decided to do KYC.
Why KYC is dangerous and useless.If they want to dive more into privacy, there are many resources.
Bitcoin privacy resources.But it's not our responsibility if a casino or another platform leaks our documents due to poor security measures from their end. Although we should be careful where we submit KYC, even the most trusted platforms have faced data leaks, and this is something we can't predict nor can we have a zero digital footprint. Unfortunately, it seems that we can't delay the inevitable forever, as careful as we may be, there's always a possibility of having our documents leaked on the darknet.