What if they monitored people who bought Bibles, Korans, or novels like 1984?

Via WSJ:

Banks and credit-card companies are discussing ways to identify purchases of guns in their payment systems, a move that could be a prelude to restricting such transactions, according to people familiar with the talks.

The discussions are preliminary but could be deeply controversial. Gun-rights groups have long resisted any effort to monitor which Americans own guns; there are federal laws limiting the government’s use of electronic databases of gun sales.

The financial companies have explored creating a new credit-card code for firearms dealers, similar to how they code restaurants, or department stores, according to people familiar with the matter. Another idea would require merchants to share information about specific firearm products consumers are buying, some of the people said.