NITA BHALLA  FROM internet shutdowns and online surveillance to social media taxes and arrests for anti-government posts, "digital authoritarianism" is a threat to basic freedoms and rights in many African countries, researchers said yesterday. A study by the African Digital Rights Network (ADRN) focusing on 10 countries found governments used a plethora of measures over the last two decades to stifle people's ability to organise, voice opinions and participate in governance online. "Our research shows online civic spaces are being closed through various repressive actions, including unwarranted arrests, unwarranted surveillance and various forms of intimidation," said Juliet Nanfuka from the…