A new gun control bill calls for banks and credit card companies to track and provide transaction data to the feds on some firearm purchases as a way of tracking people who the government suspects might be planning mass shootings.

Rep. Jennifer Wexton's (D–Va.) "Gun Violence Prevention Through Financial Intelligence Act" would require the Financial Crimes Enforcement Network (FinCEN) to "request information from financial institutions for the purpose of developing an advisory about the identification and reporting of suspicious activity." The bill's aim is to identify a consistent purchasing pattern among people who buy firearms and firearm accessories in order to conduct "lone wolf acts of terror" and expose how the firearms market in the United States is exploited by would-be mass shooters.

"Banks, credit card companies, and retailers have unique insight into the behavior and purchasing patterns that can help identify and prevent mass shootings," Wexton explained in a statement. "The red flags are there—someone just needs to be paying attention."

The New York Times reports that Wexton's bill was inspired in part by Times columnist Andrew Ross Sorkin's 2018 investigation on several mass shootings that have happened since the Virginia Tech shooting in 2007. Sorkin's work revealed that in at least eight of the 13 mass shootings that killed 10 or more people within that time span, the perpetrators used credit cards to finance their killing sprees. James Holmes, who killed 12 people at a movie theater in Aurora, Colorado, used a credit card to purchase more than $11,000 worth of guns, grenades, and other military gear prior to his rampage. Omar Mateen, the Pulse nightclub shooter in Orlando, Florida, ran up $26,532 in charges across six credit card accounts in the 12 days leading up to his attack.

Wexton's bill assumes it's possible to tell who is a threat based on tracking credit card activity. Unfortunately, government's past attempts to identify "red flags" by analyzing transaction data has resulted in, as Reason's Elizabeth Nolan Brown puts it, banks "cast[ing] as wide a net as possible," when deciding what activity gets reported. Banks fear the consequences of being accused of not doing enough to comply with reporting laws and requests. Brown notes that banks' attempts to monitor customers' transaction data in order to identify human traffickers for the government have resulted in the creation of an extremely broad definition of what constitutes suspicious activity, including things like running up large grocery bills and renting DVDs in bulk.

Almost half of gun owners report owning at least four guns, which makes it relatively easy to see how any gun owner could come under suspicion should the government deputize financial institutions to monitor "suspicious" gun transaction patterns. There is no way to determine whether or not someone is spending a lot of money on guns to commit a crime or just because they like them since the transactions are identical on paper. Spending a lot at a gun store might be less unusual than Wexton seems to think.

Wexton also acknowledges that "historically, retail-level purchase information…has been hard to obtain" and that the effectiveness of the advisory would be largely dependent upon the willingness of merchants to share information on "specific firearms products and accessories."

Representatives from both Visa and Mastercard did not respond to Reason's request for comment on Wexton's current bill. But both companies have expressed reservations in the past about, as Visa spokesperson Amanda Pires told the Times last year, "setting restrictions on the sale of lawful goods or services."

Pires also noted that "asking Visa or other payment networks to arbitrate what legal goods can be purchased sets a dangerous precedent."