Fire Dog Lake wrote an article trying to explain the unconscionable position of the Obama Administration to be able to fire a government employee who testifies under oath. It would not matter whether or not that person is subpeonaed or not.
Their flawed reasoning is that the employee would have information that was not available to the general public, and therefore exposing that information in a court of law is tantamount to treason of the employer and a firing offence.
This position is key to their argument against whistle blowers who give information to the FBI or other agencies to bring forth corruption, fraud, and other charges against their employer (the US government) .
The first amendment is being challenged because the Obama administration doesn't feel that free speech should be extended to testifying under oath at court proceedings. They are arguing therefore that it would be in an employees interest to LIE under oath in order to keep their job. This leaves an employee in an untenable position to either follow the law to tell the truth about a matter or to lie and/or plead the 5th in order to keep their job.
The case that was heard was Lane v. Franks and SCOTUS is struggling to come to terms with the Obama Administrations argument. Links are below to the FDL article as well as the transcripts in the SCOTUS arguments.