Sources: multiple federal agencies raised concerns about Grok's safety and reliability in recent months, before DOD approved Grok for use in classified settings

Block says it is laying off 4,000+ of its 10,000+ employees, saying AI tools have changed “what it means to build and run a company”; XYZ jumps 15%+ — Block said Thursday it's laying off more than 4,000 employees, or about half of its head count. The stock skyrocketed as much as 24% in extended trading.