Shares of PepsiCo ($PEP) were in the spotlight on Friday after the Federal Trade Commission announced it plans to sue the consumer giant on allegations of price discrimination, with retail sentiment turning cautious.

The Robinson-Patman Act was passed in 1936, but the federal government stopped enforcing it during the deregulation of the 1980s. The FTC resumed its enforcement in December when it sued Southern Glazer’s, the largest U.S. distributor of wine and spirits.

The FTC is suing PepsiCo for allegedly rigging the market by offering “unfair pricing advantages” that can contribute to inflation.

Although there are millions of options to choose from, Americans have their preferred soda brands, with Coca-Cola, Dr. Pepper, and Pepsi being among the most popular in terms of generated revenue. Related: PepsiCo makes surprising move with irresistible snack food brand PepsiCo is an American multinational food,

The Federal Trade Commission sued PepsiCo on Friday for offering preferential pricing to a large retailer, whom a source familiar with the matter confirmed was Walmart.

The FTC said the alleged activity forces many Americans to pay inflated prices for PepsiCo products unless they shop at this store.

In the suit, the FTC said PepsiCo gave pricing advantages to one large chain but did not give those incentives to smaller retailers.