On target projects, credit cards are charged when a project reaches its goal. If the project has already reached its goal (or is a pre-order with no goal) then they are charged immediately. PayPal pledges are always charged immediately but are refunded on a target project if the project does not reach its goal. You can cancel your pledge at any time before your pledge is fulfilled.
We use a Payment Gateway to store card details and under no circumstances does PledgeMusic hold credit card details.