I heard a work story recently where the new employee (who hadn't yet been demoralized) spoke up in staff meeting, challenging the boss on a policy. The rest of the staff sat, quietly mesmerized and inspired, curious as to what the boss would say.
And while no new policies immediately resulted, the staff finally saw that the boss could be stood up to, challenged with rationale and facts in the hopes of making a case for how work could be done differently (and better).
Speaking truth to power does this. Speaking truth may not result in an immediate about face from power, but speaking truth does inspire the rest of us to realize we all have a weapon in our arsenal that can equip us for battle against the power and authority over us.
We must be careful when wielding our truth, but brandish it we must. The battle will not be won immediately, but in the end, I've always found it goes to the truth-tellers.