That is totally not banks business what I am doing with in my phone. That is a violation of privacy. How would they even find out that I am gambling on my phone? By looking on the screen? If that is ok, then it would be ok to browse my chats and phone call list? Absolutely not. An employee is not a slave that has no right to spend a minute to take a rest. Then everyone should immediately get fired as soon as they went to a toilet to get a cup of water.
For addicted anything is possible, but from my experience, to steal from bank, where cash is monitored by dozens of cameras, and UI wont allow to make a transaction to a random account without receiving a permission, is close to impossible. Imo the maximum what addicted can steal is money from his colleagues.
You are indeed right, a person has the right to be at least minimally distracted, the main thing is that he can perform his duties well and this does not affect the final result. If all workers are driven into a corner by an employment contract in which nothing can be done, then they will turn into slaves. It is very important that this line is not violated, because such things cause great depression among workers, which will subsequently have a very destructive effect on their lives. Maintaining a balance is the main thing.
When we work for other people or companies then there are written and unwritten rules that we should obey for the good of us and also the place we work, although maybe gambling is our right and privacy but at least we don't do it at work, because it will only damage our reputation and also the place we work, in my opinion, it is important to maintain integrity and trust in the work environment, especially in sensitive areas such as finance, because Employees who Engage in gambling in the workplace can pose a big risk and we even often hear and read news how an employee uses company money to gamble, so I think the action of dismissal and also blacklist the employee can be a solution and also a lesson for other employees not to do the same.