In all honesty you will not be fired for speaking up. You do however run the risk of the management making work a very uncomfortable place for you in an effort to get you to quit. Probably cut your hours and give you the worst shifts and constantly ride your ass. I truly hate to say it but people who act in that manner will not be sympathetic to you and see you as a problem and use that to justify thier actions. Hold your head up, ignore them, and quietly find another job.