WASHINGTON — The federal government is prosecuting leakers at a brisk clip and on novel theories. It is collecting information from and about journalists, calling one a criminal and threatening another with jail. In its failed effort to persuade Russia to return another leaker, Edward J. Snowden, it felt compelled to say that he would not be tortured or executed.

These developments are rapidly revising the conventional view of the role of the First Amendment in national security cases. The scale of disclosures made possible by digital media, the government’s vast surveillance apparatus and the rise of unorthodox publishers like WikiLeaks have unsettled time-honored understandings of the role of mass media in American democracy.

This is so even where the government was the nominal loser. Consider the case of Pfc. Bradley Manning, who dodged a legal bullet on Tuesday, winning an acquittal on the most serious charge against him: that releasing government secrets to the public amounted to “aiding the enemy.”

But a dodged bullet is still a bullet.

The military judge in Private Manning’s case ruled last year that there was no First Amendment problem with the government’s legal theory. Providing classified information for mass distribution, she said, is a sort of treason if the government can prove the defendant knew “he was giving intelligence to the enemy” by “indirect means.”