I did digital (web) QA a few years back, and we used a special admin account for Facebook testing. Basically a fake persona that is all locked-down to be super-private and not shared anything. But the only person who used it was a QA Manager, so such testing was concentrated with that person.
However, Facebook would go through bouts of closing accounts that looked fake.
They also change their settings screens alot to trip-up users and I was constantly auditing these admin accounts to keep them from sharing-out to the greater Facebook community or servers. Not sure if the new laws made this aspect any easier?