The President may have legal bases to avoid some of the congressional subpoenas, and may face few legal consequences for ignoring the subpoenas. However, if you are served with a subpoena, you should respond. You may have rights to quash or modify the subpoena. If you do not respond, you could be fined or jailed. It may be useful to contact an attorney if you receive a subpoena to produce information, since you may have a duty to protect customer information.