Just hours after news spread online that Nicolás Maduro, Venezuela's ousted president, was arrested by U.S. forces, social media was overrun with photographs depicting him in handcuffs, escorted by drug enforcement agents or surrounded by soldiers on a military aircraft. The images were fake — the likely product of artificial intelligence tools — in what experts said is one of the first times that A.I. imagery has depicted prominent figures while a historical moment was rapidly unfolding.