I do not think that everyone considers any, even the largest and most famous casino, to be reliable in matters of maintaining confidential and personal information. 

Long-term experience of using the Internet clearly tells us that confidential data leaks periodically occur due to the deliberate hacking of databases by hackers, or the sale of these databases of casino users by corrupt employees.  Finally, random, unintentional database leaks that occur simply due to inattention or negligence of individual inexperienced employees in their work.  Experience shows that such events always occur, but of course the selection of personal data bases is always random. 
But no one can give you a guarantee that the very database that contains information about you will not be stolen and made public in this way!