Amazon’s plan to expand in the $830 billion grocery industry is rattling potential competitors, but also runs the risk of further aggravating congressional concerns that the e-commerce giant is behaving like a monopoly.

The company founded by Jeff Bezos, the world’s richest man, and others like Facebook and Google are already under scrutiny by President Trump and lawmakers because of their market power, as well as their control of platforms that give them a powerful advantage over business customers who are also competitors.