First and foremost, the goal is to protect the players by asking questions about the unusual activity on the account, to protect from losing large amounts of money, potential fraud, or identity theft.
On top of protecting the players, it’s a regulatory requirement to ensure that no money laundering occurs on the accounts. We never assume that illegal activity is occurring. but if such a problem does arise we will be responsible for the situation that could have been avoided, that may result in financial fines and penalties.