Originally Posted by
aster
I'm not so worried about passengers unlocking the lav doors, but rather locking an empty lav when nobody is looking just for the sake of pissing off other passengers who will think that some diva is taking ages with her make-up.
Ha ha, that would be hilarious!
However, I think a FA would knock and check, worst case scenario, they may think a passenger had collapsed in the lavatory and need help, only to find no one there.