Drew.. I am aware of HTTPS.. but well, as a former Paid Professional Paranoid (yes it really was part of my job description) I wonder how "S" Https is...
That said, I've never had a problem I could track to ON-LINE hacking.. I have had issues that traced to a retail outlet re-using my card info... As have others I know, but that does not require on-line hacking at all.
One case the hacking was done with a xerox and another a pen.
On one of those the UPS person who delivered the goods illegally ordered...
Well she was 1: The card holder of the card used and 2: A Michigan State Trooper under cover of a UPS uniform... OOPS... The next delivery that truck made was to the city jail.