Wow, I'm surprised that no-one else has put this up! This is Terry Gilliam's satirical dry-run for Brazil (1985), and even more bluntly political.

This should be the theme-short of The Pirate Bay. A team of geriatric accountants, mistreated by their new bosses, revolt and turn pirate, sailing their office building out into the metropolis and raiding banks etc; filing cabinets are used as cannons. Great fun, and with a real bite.

imdb tt0215685