“We were not forced by anyone to restrict trades,” Robinhood CEO Vlad Tenev told CNBC on Thursday evening. “We did this on our own, but there was no liquidity problem. We did this proactively.”

Some employees said they feared the company was straying from its mission statement according to messages posted on Blind, an anonymous message posting service that verifies corporate email addresses before allowing posting, reviewed by tech website The Information.

“This sets a horrible precedent,” one message read. The “blowback” will be like that when the app crashed during a March rally, except “on steroids,” the user wrote.

Enraged users filed a proposed class action suit. Regulators have taken notice. Congress is gearing up for hearings. The Securities and Exchange Commission, the country’s top financial regulator, said on Friday it would “closely review actions” by companies that “may disadvantage investors or otherwise unduly inhibit their ability to trade certain securities.”