The library itself sets the limit on how many films a user can borrow. They do this because they have a budget that needs to cover as many patrons as possible. When you borrow a film through our service, you will be informed how many loans you have remaining. If you have reached your loan limit, you will also see the date when you can borrow again.
If you have created a user account in our service, you can check how many loans you have left by clicking on "My Profile".