The rights chief said Wednesday from Geneva digital communications technology was opening doors to facilitate global debate and foster international democratic conversations. New technology, however, comes with a dark side, she said.
"[We've] seen how new technologies are being developed covertly, often to facilitate these practices, with chilling efficiency, "she said.
In February, members of Civil Liberties Committee in the European Parliament said there was a trust deficit hanging bilateral relations with the United States because Washington's cyberespionage campaign, the details of which were leaked to the media last year by Edward Snowden, a former contractor for the National Security Agency.
Pillay said governments have the right to use targeted surveillance measures provided they're "case-specific."
"At the same time, the secretive nature of security surveillance in many places inhibits the ability of legislatures, judicial bodies and the public to scrutinize state powers," she said. "This lack of transparency, together with a lack of clear and appropriate limitations to surveillance policies and practices, creates serious obstacles to ensuring that these powers are not used in an arbitrary or indiscriminate manner."