What do the fire man do for a living? why is this Ironic?

Firemen burn things that they are told to. Whatever they burn defies the society. It is ironic because firemen as we know them fight fires and put them out.

What do the "firemen" do for a living? The firemen burn down houses that contain books. This is ironic because today firemen try to control fires and stop them ... Books are compared to birds because as birds fly away books can trigger thoughts in our mind that lead to many ideas.