Bill Gates warns young people of four major global threats, including AI
But try not to worry, kids
Facebook buildings evacuated after deadly nerve agent was detected in mailroom (updated)
No injuries have yet been reported -- HazMat crews say all tests for toxins turned up negative
Facebook tracks the location of users it believes are potential threats
Don't swear at Mark Zuckerberg
Hoax bomb threat emails demanding Bitcoin cause nationwide evacuations
Police say the threats are not credible
