I don’t know anyone who would argue the media should never be forced to reveal any information they receive from sources, though the legislation that’s been pending for a year in the House and Senate calls for a complete privilege for sources’ names.
On the other hand, I don’t know anyone who would argue the government should use the media to do their investigation for them.
The case in this story may or may not involve national security, which is probably one of the strongest arguments for forcing testimony.