Shares of the social media giant Twitter saw a 6 percent decline in value Wednesday, the same day the company’s CEO Jack Dorsey testified before the Senate Intelligence Committee regarding election meddling during the 2016 presidential race.

Dorsey appeared with Sheryl Sandberg, Facebook’s Chief Operating Offer, during the hearing. According to a report from CNBC, the hearing is designed to investigate any “meddling and abuse” on social media platforms and how the companies plan to combat malignant users.

“Abuse, harassment, troll armies, propaganda through bots and human coordination, misinformation campaigns, and divisive filter bubbles – that‘s not a healthy public square,” Dorsey said during his opening remarks, according to The Guardian. “We acknowledge the real-world negative consequences of what happened, and we take full responsibility to fix it,” he added.

Social media platforms like Twitter and Facebook have also been accused of harboring an anti-conservative bias. Some prominent Republicans have accused Twitter of “shadow banning” conservative voices. President Donald Trump addressed these allegations in July in a tweet.