Trump Faithful Descended on D.C., but Not Everyone Made It Onto a Yacht The celebrations ahead of Donald J. Trump’s inauguration included passionate members of his base along with Trump-loving power brokers partying wildly all around them, but just out of reach.

When Hackers Descended to Test A.I., They Found Flaws Aplenty The hackers had the blessing of the White House and leading A.I. companies, which want to learn about vulnerabilities before those with nefarious intentions do.