Treason Revisited

The subject of treason came up in a rerun of the television series I was watching last week.   Naturally, the heroes got involved in foiling a terrorism plot.  While being given classified government information during a briefing they were told that if they divulge anything about it they would be committing treason.  I didn’t think anything of this at the time, perhaps because recently I’ve heard similar statements on several other TV shows.