https://www.eff.org/deeplinks/2023/10/mastercard-should-stop-selling-our-data

"That's why EFF has joined a campaign, led by the U.S. Public Interest Research Group (U.S. PIRG), to call on Mastercard to limit its data collection and stop selling cardholder information."

"Why make this ask of Mastercard? As U.S. PIRG explains in its report accompanying the campaign, the company’s position as a global payments technology company affords it "access to enormous amounts of information derived from the financial lives of millions, and its monetization strategies tell a broader story of the data economy that’s gone too far.""

"Knowing where you shop, just by itself, can reveal a lot about who you are. Mastercard takes this a step further, as U.S. PIRG reported, by analyzing the amount and frequency of transactions, plus the location, date, and time to create categories of cardholders and make inferences about what type of shopper you may be. In some cases, this means predicting who’s a “big spender” or which cardholders Mastercard thinks will be “high-value”—predictions used to target certain people and encourage them to spend more money."