According to the Washington Post, the secrecy around today's 1/6 committee hearing is "in part due to credible security threats to a witness."
https://www.washingtonpost.com/national-security/2022/06/27/jan-6-committee-announces-surprise-tuesday-hearing-offers-few-details/
@Coctaanatis , I'd rather give protection to these witnesses than supreme court. They can afford their own protection.