Global media freedom is at its lowest level in 10 years, a study by freedom of expression campaign group Article 19 in collaboration with political and social database V-Dem showed on Wednesday. The study, which measured press freedom in 172 countries, said Turkey, Brazil, Bangladesh, Burundi and Macedonia show the most significant decline in free speech over the last 10 years.

“Internet censorship has become more pervasive since 2006, the year when Twitter was launched,” the study said. “Algorithms are increasingly used to remove legal and illegal content with little transparency over the process or consideration of human rights.” The study added that “much of the world’s content is now regulated by the community standards of a handful of internet companies, whose processes lack transparency.”

It also said that governments are monitoring private communications like “never before” by passing laws allowing extensive digital surveillance. “Governments are using unprecedented legal and other measures to silence dissenting voices and protest by individuals and civil society organisations,” the study said.

“For the first time, we have a comprehensive and holistic overview of the state of free of expression and information around the world,” Article 19 Executive Director Thomas Hughes said. “Unfortunately, our findings show that freedom of expression is under attack in democracies as well as authoritarian regimes.”

On the upside, the Article 19 report said that right to information laws have been passed in 119 countries. It listed Tunisia, Kyrgyzstan, Romania and Sri Lanka as the countries where free speech improved the most.