A dumbed-down, but forthright article on why US drone strikes are not necessarily OK.
US officials defended the policy after al-Qaeda leader Abu Yahya al-Libi was reportedly killed in a drone strike earlier this week.
US Defence Secretary Leon Panetta said that the US would “continue to defend ourselves”.
Ms Pillay said she had suggested to the Pakistani government that they invite the United Nations Special Rapporteur on Summary or Arbitrary Executions to investigate some of the incidents.
Ms Pillay said drone attacks were beyond civilian or military control.
The US has also carried out drone strikes as part of military operations in Yemen, Somalia and Afghanistan.
But correspondents say drone strikes are highly controversial as significant numbers of innocent bystanders are killed along with intended targets.
The policy has contributed to a recent worsening in relations between the US and Pakistan.
One controversial aspect of drone attacks in Pakistan is that they are not conducted by the US military - which is expected to comply with the laws of armed conflict - but by the Central Intelligence Agency, whose operations are far from transparent, the BBC’s defence correspondent Jonathan Marcus reports.
The legality of the operations is also brought into question by the fact that Pakistan, unlike neighbouring Afghanistan, is not a zone of armed conflict, he adds.