U.S. press freedom has suffered its steepest decline in a decade due to the government’s efforts to block reporting on the NSA spying scandal exposed by NSA whistleblower Edward Snowden, obstruction of information, and the decimation of media diversity.

This is according to global index on media freedom (pdf) released Thursday by U.S.-based Freedom House.

Filed annually since the 1980s, the 2014 report finds that the U.S. suffered a “significant negative shift” from 2013: on a scale where countries are ranked from zero to 100, with lower numbers representing greater freedom, the U.S. dropped from 18 to 21 points.

“The U.S.’s score suffered its largest year-on-year decline in a decade,” Jennifer Dunham, Senior Research Analyst at Freedom House, told Common Dreams. “In other years, the U.S. may have declined (or improved) one or two points, but never 3.”

The report cites “attempts by the government to inhibit reporting on national security issues” as the number one reason for this plummet.

Factors include “government attempts to control official information flows, particularly concerning national security–related issues; the legal harassment of journalists with regard to protection of sources; and revelations of surveillance that included both the bulk collection of communications data by the National Security Agency (NSA) and the targeted wiretapping of media outlets.”

Responding to the report, Betty Yu from the Center for Media Justice told Common Dreams, “In the U.S., the government has tried to suppress and downplay the severity of the Edward Snowden NSA revelations in the press.To many of us in the social justice movement, we know that surveillance and eavesdropping on communities of color and progressive movements is not new. But his revelations exposed that every person in the U.S. is being spied on. Fighting digital surveillance and the right to privacy is absolutely a freedom of the press issue. We need to be allowed to communicate and share information freely.”

According to the report, “Ongoing challenges include the threat to media diversity stemming from poor economic conditions for the news industry. Researchers also slam the “limited willingness of high-level government officials to provide access and information to members of the press,” including failure to respond to Freedom of Information Act Requests.