"We will certainly have legislation which will limit or prevent contractors from handling highly classified technical data. And there will be some other things," said Feinstein after a closed-door briefing about the U.S. government's surveillance programs.
Feinstein also said National Security Agency Director Keith Alexander had pledged to make public on Monday a list of terrorist efforts that had been thwarted by the programs.
The FBI is preparing charges against NSA leader
The United States has launched a criminal investigation and is taking "all necessary steps" to prosecute Edward Snowden for exposing secret US surveillance programs, the FBI director said Thursday.
"These disclosures have caused significant harm to our nation and to our safety," Federal Bureau of Investigation Director Robert Mueller told lawmakers at a hearing of the House Judiciary Committee."
As to the individual who has admitted to making these disclosures, he is the subject of an ongoing criminal investigation," he said.
"We are taking all necessary steps to hold the person responsible for these disclosures."
The FBI chief's comments offered the first explicit confirmation that the US government was pursuing Snowden, the 29-year-old American IT specialist who has admitted to leaking information about far-reaching surveillance programs.
Snowden, who worked as a subcontractor handling computer networks for the National Security Agency (NSA), is in Hong Kong, a semi-autonomous Chinese territory, where he has vowed to contest any possible extradition in court.
An ex-CIA worker Edward Snowden’s exposure of a once-secret U.S. electronic surveillance program has spawned a criminal investigation and congressional questions about the ability of a low-level employee to breach national security.
The Obama administration said the case is under investigation. With Snowden having fled to Hong Kong, congressional leaders are demanding his indictment and extradition for what one senator called treason.
“There is, obviously, an investigation under way into this matter,” said White House press secretary Jay Carney.
House Intelligence Committee Chairman Mike Rogers, a Michigan Republican, said in a statement that “anyone responsible for leaking classified information should be punished to the fullest extent of the law.”
Senate Intelligence Committee Chairman Dianne Feinstein, a California Democrat, has scheduled a June 13 briefing by law enforcement and intelligence officials for all members of the Senate on the NSA program.
Edward Snowden, 29 year-old provided detailed information about a wide-reaching National Security Agency Internet surveillance program to journalists and then revealed his own identity voluntarily.
The United States are trying to find an espionage law in Hong Kong similar to the one in the US to extradite Edward Snowden. Former NSA officer would likely come under the Espionage Act of 1917, the same law the US government has used against other civilians who have disclosed classified information without authorization.
Some lawyers with expertise in extraditions say it would be a challenge for Mr Snowden to circumvent the treaty between the US and China signed in 1998 that allows the exchange of criminal suspects.
"If you're an American citizen, fleeing the US isn't such an easy thing," Robert Anello, a New York lawyer who has handled extradition cases, told the Telegraph newspaper.
"They [China] are not going to put at risk their relationship with the US over Mr. Snowden, and very few people have found that they have the clout to persuade another country to go out of their way for them," Mr Anello added.
According to the daily, for a person to be extradited, the alleged act must be a crime in both countries, and as Hong Kong is under the ultimate control of China, the treaty allows to refuse any transfers that would implicate the "defense, foreign affairs or essential public interest or policy" of China.
Meanwhile, former CIA case officer Bob Baer revealed on CNN Sunday evening that intelligence officials were possibly considering Edward Snowden’s case as Chinese espionage.
“Hong Kong is controlled by Chinese intelligence,” Baer said. “It’s not an independent part of China at all. I’ve talked to a bunch of people in Washington today, in official positions, and they are looking at this as a potential Chinese espionage case.”
Speaking about any chances of China to extradite Snowden, Baer claimed, that the USA “will never get him in China”.
“They’re not about to send him to the United States and the CIA is not going to render him, as he said in the tape, is not going to try to grab him there,” Baer said.
Edward Snowden was brought up in North Carolina and Maryland. In 2003 he enlisted in the US Army, intending to fight in the Iraq War, but was discharged after breaking both legs in an accident during a Special Forces training programme. Snowden said he wanted to fight in Iraq because he felt an obligation to “help free people from oppression”, but that “most of the people training us seemed pumped up about killing Arabs, not helping anyone”.
He was employed by the NSA as a security guard at one of its covert facilities, and then by the CIA, working on IT security. In 2007 was sent to join a CIA station in Geneva.
He considered turning whistleblower, but changed his mind after Barack Obama was elected President in 2008, with a promise to reform the policies of the White House.
Until three weeks ago, Snowden worked at an NSA office in Hawaii. On May 20 he left Hawaii for Hong Kong where, according to him, “he would be in a place that might be able to resist US prosecution attempts”.
Voice of Russia, Reuters, Bloomberg, DPA, Reuters, AFP, the Telegraph, Media ITE, the Independent, CNN, petitions.whitehouse.gov, RIA