Anything you say can and will be used against you in a court of law. This especially applies to congressional testimony. No one WANTS to be subpoenaed by Cong

Anything you say can and will be used against you in a court of law. This especially applies to congressional testimony. No one WANTS to be subpoenaed by Congress. There is no upside. If you want to talk to congress honestly, Mark Z could do that anyway, at any time. There is only downside in testifying before congress.