Utility Workers Union of America
AFL - CIO Local 127

Be aware that there sometimes is a difference between what you know actually occurred and what you can prove as a matter of law.  You’d be kidding yourself if you thought that there’s never been an instance in which a worker was in fact retaliated against by his or her employer for having engaged in behavior that is legally protected but was unable to prove that the retaliation took place.  Still, don’t let this prevent you from asserting your rights.  There have been plenty more instances where the agency charged with enforcing a law moved aggressively against an employer trying to prevent an employee from asserting rights under that law.  After all, if all employees are successfully intimidated into not using the provisions of the law, that agency becomes useless.
—Adapted from The Union Member's Complete Guide, by Michael Mauer