This is the reason why we should avoid public internets, always make sure to have your own internet and if you most connect to public wifi use a privacy enhance connection, browsers.
I agree completely, but also would have to add on that most of these problems arise from people using VPN's, proxies and TOR browser. Especially free VPN's like Proton VPN or Ghost VPN. A lot of people don't know how often their IP has been used by millions of other people, and some of them have registered on said casino and/or did some shady things with the IP that was assigned to them, and is now assigned to the new user (who has no idea).
It’s a trivial issue since some multiple account abusers are using this reason as an argument to hide their abuse because they knew VPN can be resulted to share IP. This is the reason why some casino completely ban the use of VPN.
The main challenge on cases like this is we don’t know who’s telling the truth because casino will not release evidence publicly. Only arbitrator can check this that usually sided to casino based on some cases that I follow with same issue.
So I believe on.y few users is genuinely using VPN without understanding the repercussion.