From social media sites like Facebook and Instagram to streaming services like Amazon Prime, most Americans leave a growing digital footprint every day.

Personal details, including email addresses, phone numbers, shopping habits, birthdays, and more, are increasingly compiled into data profiles that companies and data brokers can monetize. These profiles are often created without the full knowledge or informed consent of consumers.

A University of Pennsylvania study found that 79% of Americans feel they have little control over what marketers learn about them. Experts call this “data fatigue”—the sense that many consumers are aware of their data being collected but feel powerless to stop it. The same study revealed that more than half of respondents didn’t fully understand the extent of how companies use their data. This data collection approach is now moving from online platforms to in-store settings, including local grocery stores.

“Retailers today are doing everything they can to gather as much information about you as possible because it represents a new revenue stream,” said R.J. Cross, director of Public Interest Research Group’s Don’t Sell My Data campaign. “Nearly every company you shop at today is in the business of selling your data. You and your data are their latest product.”

The data broker industry was estimated at $319 billion in 2021, with expectations to exceed $545 billion by 2028. Whereas retailers once relied on third-party brokers to understand consumer trends, they are now collecting consumer data directly through loyalty programs, location tracking, app usage, and digital receipts.

“My face is part of the data that’s captured, along with my behavior, which reveals more about my age, gender, and ethnicity,” said Mitul Jain, founder and CEO of Refive. “All these data points can be combined with other small pieces of information I leave behind during my shopping journey.”