Democratic presidential frontrunner Bernie Sanders thinks the federal government must do more to ensure that people’s internet browsing histories aren’t tracked and sold to big companies.

Sanders joins fellow senators Mark Warner and Ron Wyden in calling for action over the secretive industry that makes millions of dollars tracking and selling the internet behavior of ordinary internet users. A joint investigation by Motherboard and PCMag published Monday found that Avast antivirus, which has more than 435 million users around the world, is selling its users’ browsing habits to companies like Google, Microsoft, McKinsey, Pepsi, Yelp, Condé Nast, and Home Depot through a subsidiary called Jumpshot.

“No reasonable person would expect antivirus software to be selling off their private browsing data to the highest bidder,” a spokesperson for Sanders told Motherboard. “Unfortunately, this story fits a pattern of the largest technology corporations trampling over the rights of consumers with near impunity.”

Our investigation found that Jumpshot sells “every search. Every click. Every buy. On every site.” One of its products is a so-called All Clicks Feed.” Huge corporations have bought this data, which tracks users all over the internet, including on porn sites.

The Federal Trade Commission (FTC) said Monday that the agency is “very familiar with how these markets for data operate, and will not hesitate to take appropriate action as necessary where we find conduct that violates the laws we enforce.”

Sanders' statement says that’s not enough: “If the FTC is to regain credibility and serve the public interest, it must take a stronger stand on issues like this one.”

Joseph Cox contributed reporting.