Bank card fraud detection and/or prevention methods

1. A bank card fraud detection and/or prevention method comprising:

a. identifying, using a computer, a test site comprising a first merchant associated with bank card transaction frequencies which exceed a predetermined threshold value indicative of potentially fraudulent bank card activity, said predetermined threshold value a percentage of all bank card transactions over a predetermined time interval;

b. identifying, using the computer, a first plurality of bank cards used at said first merchant associated with said transaction frequencies which exceed said threshold value;

c. from said first plurality of bank cards used at said first merchant, identifying, using the computer, a second plurality of bank cards which have reversals of charges made at said first merchant before said charges get to posting files such that said charges do not appear on cardholder statements, said reversals of said charges as made such that said charges do not appear on said cardholder statements indicating at least some of said second plurality of bank cards are fraudulent and were being tested at said first merchant to determine if said second plurality of bank cards worked; and

d. from said second plurality of bank cards, determining, using the computer, a common point of compromise, wherein said common point of compromise is a second merchant at which at least some of said second plurality of bank cards were used.

2. The method of claim 1 further comprising identifying, using the computer, other bank cards used at said second merchant, wherein said other bank cards are potentially compromised.

3. The method of claim 1 wherein said identifying bank card transaction frequencies which exceed a predetermined threshold value further comprises searching, using the computer, a bank card database using a bank card transaction frequency query.

4. The method of claim 3 wherein said bank card transaction frequency query is based upon exceeding said threshold value over said predetermined time interval.

5. The method of claim 4 wherein said time interval is a single day.

6. The method of claim 5 wherein said transaction frequency is one percent of all bank card transactions during said single day.

7. The method of claim 1 wherein said identifying said bank cards used at said first merchant identified as being associated with said transaction frequencies which exceed said threshold value further comprises searching, using the computer, a bank card database based upon said first merchant to identify bank cards which were used at said first merchant.

8. The method of claim 1 further comprising providing, using the computer, a list of said potentially compromised bank cards.

9. The method of claim 8 further comprising deactivating, using the computer, the bank cards on said list of potentially compromised bank cards.

10. The method of claim 9 further comprising issuing, using the computer, new bank cards to replace the deactivated ones.

11. A non-transitory computer-readable medium having computer-executable instructions, to be executed by a computer, for performing a bank card fraud detection and/or prevention method comprising:

a. searching a bank card database using a bank card transaction frequency query to identify a test site comprising a first merchant associated with bank card transaction frequencies which exceed a predetermined threshold value which is indicative of potentially fraudulent bank card activity, said predetermined threshold value a percentage of all bank card transactions over a predetermined time interval;

b. searching the bank card database using a query based upon said first merchant to identify a first plurality of bank cards used at said first merchant;

c. from said first plurality of bank cards, identifying a second plurality of bank cards which have charge reversals that are made at said first merchant before said charges get to posting files such that said charges do not appear on cardholder statements, said reversals of said charges as made such that said charges do not appear on said cardholder statements indicating at least some of said second plurality of bank cards are fraudulent and were being tested at said first merchant to determine if said second plurality of bank cards worked; and

d. searching the bank card database using a query based upon said second plurality of bank cards to determine a common point of compromise, wherein said common point of compromise is a second merchant at which at least some of said second plurality of bank cards were used.

12. The non-transitory computer-readable medium of claim 11 further comprising:

a. searching the bank card database using a query based upon said second merchant; and

b. identifying other bank cards used at said second merchant, wherein such other bank cards are potentially compromised.

13. The non-transitory computer-readable medium of claim 11 wherein said bank card transaction frequency query is based upon exceeding said threshold value over said predetermined time interval.

14. The non-transitory computer-readable medium of claim 13 wherein said time interval is a single day.

15. The non-transitory computer-readable medium of claim 14 wherein said transaction frequency is one percent of all bank card transactions during said single day.

16. The non-transitory computer readable medium of claim 11 further comprising instructions for generating a list of all bank cards associated with at least one of said first and second merchants, which bank cards are all potentially compromised.

17. The non-transitory computer readable medium of claim 16 further comprising instructions for deactivating the bank cards on said list, or noting that such cards are to be deactivated.

18. The non-transitory computer readable medium of claim 17 further comprising instructions for issuing new bank cards to replace the deactivated ones, or noting that replacement cards are to be issued.