If it is a free trial, why are the credit card details required?

TRuDrive.net free trial allows you to evaluate our online backup, storage and sharing service. Your credit card details are collected to give you a hassle-free transition to an TRu Cloud paid subscriber, which means that once you have completed your free trial, you can continue using the service without any interruption. In case, you do not cancel your account within the trial period, your credit card will be billed on a monthly basis at the end of free trial period.