This is a pretty wild (and, from what I hear from my Bay Area friends, maddening) situation. Apparently, one of the routers in AT&T’s infrastructure had some corrupt memory, which was flipping bits (literally turning zeroes into ones or vice versa) and breaking people’s internet connections. And because the router in question only connected to some parts of the internet, only certain sites, like Twitter, were broken while others, like Google, loaded just fine.

It gets weirder — given enough traffic, some of the bitflipped packets even had valid checksums, so corrupted packages would come through as correct because the proper bit had been flipped on both the packet and the checksum.

I can’t help but think some of the assumptions we’ve carried with us for the past 50 or so years might need a rethink given the scale of the contemporary internet.