My wife gets far more into it than I ever have... I just don't care for the eternal cycle of people's inflated "highlight reels" of their lives.
I'm sure they did a lot of scrubbing. They are huge, high profile and constantly at risk of being taken to task for being a monopoly.
Many years back I worked for a small educational software company — a subsidiary of a larger company — and evidently some of the stuff we'd been doing was against parent company policy. So when there was going to be a "visit" (aka "audit") everybody got to work on removing every conceivable reference to anything that might invite comment or sanctions... code, email, memos, post-it notes on people's cubicle walls.. you name it.
Facebook? I'm sure they were just prepping to be poked by the FCC, SEC and Congress.