Critics have disagreed, including several NSA whistleblowers who accused the agency of violating the law by intercepting Americans’ emails in the early 2000s as part of the Terrorist Surveillance Program.

Mr. Black acknowledged that “public worries are real” and will impact NSA operations if legislation is used to prevent potential NSA “involvement in the public sector.”

That problem persists today as most U.S. infrastructure is held by the private sector, which remains wary of inviting NSA to help counter or disrupt foreign cyberattacks.

The NSA documents were obtained by the website

Terrorists’ ‘Black Summer’

U.S. national security officials are warning that jihadists are planning a major cyberattack against vital infrastructure soon.

The alert was sent following a report on a jihadist website Monday by two groups that announced in Arabic an “Open Invitation for All Hackers to Participate in ‘Operation Black Summer’ To Target U.S. Vital Services.”

The attackers plan to use the Twitter hashtag #opBlackSummer to wage electronic warfare against the United States with other jihadists.

“It is also essential to note that this raid will be a global one in which all the enemies of the United States, whether Muslims or non-Muslims, will take part,” the posting stated, noting that Osama bin Laden had advocated such attacks.

The message said one group involved in the attack is the al Qaeda Digital Army and appeared on the al Qaeda-linked website Ansar al-Mujahideen Network.

RussiaChina oppose missile defense

Russian President Vladimir Putin and Chinese President Xi Jinping issued a statement during the Chinese leader’s visit to Moscow that mentioned the “problem” of other nations’ missile defense — seen as a reference to U.S. and NATO defenses in Europe.

The statement released Friday called for building “a new type of great power relations” and called on “all nations of the world to deepen mutual understanding, coordination and cooperation on the question of missile defenses.”

The statement urged states to “be prudent” in deploying and cooperating on missile defenses, and to “oppose” one nation or a group of nations from taking steps to “unilaterally and unlimitedly strengthening missile defenses, harming strategic stability and international security.”

“We stand for the collective confrontation of the challenges and threats from ballistic missiles, preferring to confront the proliferation of ballistic missiles within the framework of international law and political diplomacy, where the security of one group of nations cannot be sacrificed at the expense of another group of nations,” the statement said.