Pakistan officials are not the only ones to express concern of the use of drones by the US. Last week, US lawmakers called on Congress and the Department of Homeland Security [official website] to address safety and security concerns [JURIST report] with the use of drone attacks domestically and to determine how to regulate their use. Earlier this month, rights groups filed a lawsuit [JURIST report] suing the US government for killing three US citizens using drone strikes. The UN last month also criticized [JURIST report] the US government's use of drone attacks, saying some attacks could constitute war crimes. A few days earlier, a UN official said the US government failed to answer [JURIST report] any of his questions regarding its use of drone attacks and noted that in the past the US has failed to provide a justification for the legality of these attacks under international law.