US Senator Elizabeth Warren and other lawmakers have raised concerns about David Sacks, the Trump administration's AI and cryptocurrency chief, potentially exceeding his 130-day annual work limit for temporary employees. In a letter, they demanded details of Sacks' workdays and locations since January. The inquiry follows a New York Times report linking Sacks to a controversial deal involving the Trump family's crypto platform and an AI chip company in the UAE. Sacks has also been managing his Silicon Valley venture capital firm, which invests in AI and cryptocurrency, during his tenure.