Peiter “Mudge” Zatko, the Twitter whistleblower, argued that regulatory agencies such as the Federal Trade Commission are not powerful enough to deal with Big Tech companies like Twitter.

Zatko, formerly Twitter’s head of security, testified in Congress Tuesday on the details regarding the social media company’s security practices. While he focused primarily on the possibility that the company’s practices make it vulnerable to foreign actors, he also noted that U.S. regulators could not do enough to oversee it.