This is just sad.
It takes a lot of work to get a ZERO % vote of confidence from your workers. Even in the worst environments, there are usually 10% or 20% of employees who management pretty much leaves alone and who think that things aren't so bad.
And now the office wants to ban posters and leaflets without management review? You'd better not work at the EU Patent Office while trying to offer weekend piano lessons/kittens you want to give away/tickets to the local community theater production of "Camelot"/etc.