Such journalistic stories are valuable and necessary, because much hush-hush information is overclassified, is kept under wraps only because it is embarrassing to the U.S. government, or is classified to keep the public in the dark about questionable government policies or actions. During the Cold War and continuing to this day, the American public is often the last to know information that is common knowledge among intelligence agencies of adversarial nations. Excessive government secrecy is a serious and underrated problem in a republic and has been exacerbated by the spike in clandestine government actions in the Bush-Obama war on terror.
If the government of a republic is going to keep secrets from its own people for their own good (faith is required here), they should keep the restricted information to the minimum. If the government drastically reduced its vast storehouse of secrets to what was truly needed to protect intelligence agents and troops in the field, whistleblowers such as Manning would have much less reason to leak and would likely have more respect for the necessity not to disclose the remaining vital information.
Most important, if a republican government cannot keep its secrets secret, it should not prosecute third-party, non-governmental recipients of the material, but should concentrate on plugging the leaks in its security system.