Why do you imagine it was stolen on-line?, doesn't he ever use it in shops?.
A friend of my wife and her husband went to New York, and took their adult son with them. While they were there the son's card was cloned - as it happens he only use dit in one place, a restaurant where he took his parents for a meal. The American Police were very happy at this, as they then knew exactly where it had happened, and were able to arrest the culprits.
Advantage of a creedit card of course, they refund your father the money that was stolen.