It may be illegal and moreover it will be not helpful. I am using Hostgator services and if u r using third party CREDIT CARD, you may need him on various occasion to confirm his details, to activate different services or at the time of help with customer service.

Also, why would anyone trust you to give his/her credit card details?

Hostgator do have the facility for PAYPAL Payment and you can use it to pay to Hostgator. For Paypal you can either link your bank account or credit card.

Hope this may help you.