Just what was it that took Facebook, Instagram & WhatsApp offline on 4th October 2021? - Dr Steve Bagley investigates! previously titled "Facebook's Day Off" Facebook announcement on the outage: https://bit.ly/C_FB-Outage The visualisation software Steve was using was BGP play, downloaded from the RIPE website. https://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: https://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com/