Reading between the lines on his FAQ page:
These charges are outrageous and reactionary because none of this has actually happened. The website has not been defaced and no credit card numbers has been billed.
He does seem to admit taking the credit card numbers. This is probably what's behind the hysterical demands for the FBI to return the property (which they won't do till they can analyse it). The felony attaches when you take the credit card number, you don't actually have to do anything with it. IANAL but I see at manyt felonies here, and additional counts for every additional card.
Jeremy's friends should not be making any long-range plans with him.
d.o.l.
Criminal Number 18F