Some number of Facebook employees ABSOLUTELY knew this was going on, quietly talked amongst themselves, maybe brought it up, but then it was knocked back down.

Some number of Facebook employees ABSOLUTELY knew this was going on, quietly talked amongst themselves, maybe brought it up, but then it was knocked back down. 100% I guarantee it. One company I worked for had plain-text passwords and it was quietly discussed (or not discussed) until we EVENTUALLY fixed it (years). Fuck facebook with a rusty pitchfork. This is the tip of the iceberg with their data-handling practices. I bet their systems are fucked throughout.