Patent ID: 7657460

Claim:
A computer-implemented method for selectively blocking a remote purchase in which a purchaser attempts to use a card number to purchase one or more of an item from a vendor's system, wherein the method is implemented in a purchase verification computer system configured to detect potentially fraudulent transactions, comprising: receiving at the purchase verification computer system, a first purchase request information set corresponding to a first purchase request to the vendor's system, wherein the first purchase information request set includes (i) an origin of the first purchase request, the origin representing either a telephone number or internet address, (ii) a card number for the first purchase request, (iii) a requested item identification for an item requested in the first purchase request, the requested item identification being associated with a first merchandise category, and (iv) a number of requested items in the first purchase request for the requested item identification; storing, to an electronic memory subsystem accessible by the purchase verification computer system, the first purchase request information set, wherein the electronic memory subsystem also stores previously received purchase request information sets corresponding to a plurality of previous purchase requests, the stored previously received purchase request information sets including a second purchase request information set corresponding to a second purchase request previously received by the vendor's system from the same origin as the first purchase request, and wherein a requested item identification from the second purchase request information set is also associated with the first merchandise category; automatically determining in the purchase verification computer system whether a number of items associated with the first merchandise category that are requested in purchase request information sets corresponding to the origin of the first purchase request exceeds a preset threshold number of items associated with the first merchandise category, wherein the number of items associated with the first merchandise category that are requested in purchase requests corresponding to the origin of the first purchase request comprises at least the number of items associated with the first merchandise category requested in the first purchase request and the number of items associated with the first merchandise category requested in the second purchase request; and automatically transmitting instructions from the purchase verification computer system to the vendor's system to block the purchase associated with the first purchase request responsive to a determination that the number of items associated with the first merchandise category that are requested in purchase request requests corresponding to the origin of the first purchase request exceeds the preset threshold number of such items.