Mark Klein, the former AT&T technician turned whistleblower who exposed the National Security Agency's (NSA) mass surveillance program, has died at the age of 79. Klein's courageous act in 2006 revealed the NSA's secret tapping of the internet backbone, sparking a national debate on privacy and surveillance.

Klein's disclosure was a pivotal moment in the history of digital rights. He came forward with documents showing that the NSA was using a secret room in an AT&T hub in San Francisco, known as Room 641A, to tap into the internet's backbone. This room was equipped with optical splitting wiretaps that created an identical copy of raw internet traffic, which was then funneled back to the NSA.

Klein's revelation confirmed that the U.S. government was accessing the internet data of millions of Americans using powers granted by Congress in the aftermath of the September 11, 2001 terrorist attacks. This was a shocking revelation that raised serious concerns about the government's abuse of power and the erosion of civil liberties.

In the years following Klein's disclosure, other whistleblowers, including Edward Snowden, came forward to reveal the extent of the NSA's surveillance activities. Snowden's leaks in 2013 exposed the NSA's widescale surveillance programs around the world, further highlighting the need for greater transparency and accountability in the government's handling of sensitive data.

Klein's bravery did not go unnoticed. He turned to the Electronic Frontier Foundation (EFF), a San Francisco-based digital rights group, which went on to sue the federal government following his disclosures. Although the case was eventually dismissed, Klein's actions sparked a national conversation about the importance of protecting digital rights and privacy.

Klein's legacy serves as a reminder of the importance of whistleblowers in holding those in power accountable. His courage in coming forward with evidence of the NSA's mass surveillance program has inspired others to do the same, and his actions will continue to have a lasting impact on the fight for digital rights and privacy.

The EFF confirmed Klein's passing, and the organization's executive director, Cindy Cohn, paid tribute to Klein's bravery and commitment to protecting digital rights. "Mark Klein was a true hero who stood up for the rights of millions of people," Cohn said. "His courage and conviction will be deeply missed, but his legacy will continue to inspire us to fight for a better future."

Klein's death is a reminder of the importance of protecting digital rights and privacy in the face of increasing government surveillance and data collection. As the world continues to grapple with the implications of mass surveillance, Klein's legacy serves as a powerful reminder of the need for transparency, accountability, and courage in the face of overwhelming power.