Mr. Snowden is a former National Security Agency (NSA) contractor who leaked information about the agency's widespread domestic surveillance operations during the Obama administration. He fled from the United States in 2013 amid possible espionage charges that could have seen him imprisoned for 30 years or more.

According to an April 1 video statement from Mr. Kennedy, Mr. Snowden performed a "critical public service by revealing to Americans for the first time that our government had been spying on millions of us ... of law-abiding American citizens in violation of numerous laws and of our fundamental right to privacy."

"His brave actions led Congress to restrict the surveillance authority of the intelligence community for the first time in forty years," Mr. Kennedy said.

"The America I love doesn't punish whistleblowers. Truth tellers who champion free speech and try to return America to its democratic and humanitarian ideals should be revered, not prosecuted," he added.

Mr. Snowden has been praised by some for his actions and vilified as a traitor by others. He says he made the disclosures because he believed the U.S. intelligence community had gone too far and infringed on civil liberties.

In 2016, the House Intelligence Committee released a declassified version of an investigative report on Mr. Snowden (pdf), describing Mr. Snowden's actions as showing a reckless disregard for Americans' safety and U.S. national security.

However, a 2020 U.S. appeals court found that the program Mr. Snowden had exposed was unlawful, and that the U.S. officials who had publicly defended it weren't telling the truth.