The Electronic Frontier Foundation (EFF) has joined a campaign to call on Mastercard to limit its data collection and stop selling cardholder information. Mastercard's data collection and monetization strategies have raised concerns about privacy and trust. The company's access to vast amounts of financial data allows it to create detailed profiles of cardholders, which can be used to target them with advertisements. The EFF argues that Mastercard should respect the trust and privacy of its cardholders and change its current data practices.