im a security guard i fell asleep at my post while i was asleep my supervisor took pictures of me to use against me for termination purposes

You bet.  Employers are well aware that whenever they discipline or discharge an employee they may face a grievance or a law suit.  Therefore, employers document the employee's misconduct in order to defend themselves against these challenges to the disciplinary decisions.  Since many cases come down to an employee's word against the employer's an employer may well use photographs, video tapes, or other evidence where they can obtain it.  When you sleep at your post, the employer has a right to take a picture of your misconduct as evidence supporting its decision to terminate your employment.