Even though a company or business may promise that your personal information is safe and will never be shared or sold to a third party. It still happens. Some computer systems are secure, those responsible may have shown due diligence and protected your information from unauthorised access.
However, those that are authorised to access your information may not be so ethical. Recently three former staff members of Enterprise Rent a Car sold details of tens of thousands of the company’s customers for many thousands of pounds.
Those details were then used to cold call the customers in a bid to sell personal injury claims
Car hire companies often provide vehicles to people who have been in an accident and need a temporary vehicle whilst theirs is repaired. The details of these people are valuable to those who can make money by encouraging accident victims to make a claim.
You can read more about this here: The register