Let's say that you work for a company that does research and development of new systems of water purification; you are directly involved in research for a revolutionary new system will change the industry.
You are seen and heard discussing the specifics of the ongoing research, and giving detailed information about the project, tools, and the progress made by your employer to employees of a competing research firm at a local restaurant. You are on your own time.
Does your company have the right to fire you?
Read your own tag line and ponder it. The anaology you posted isn't even close to being a similar situation. The employer in this case is stealing the right of the employee to exercise his rights on his own time and off the clock.
You've been told the parking lot is for storage. You've been given the law that shows that's what it is and that's about all that goes on there. How many desks, or work stations do you ever see in the parking lots? Where does the receptionist sit to do her nails, in the parking lot, or inside the door?
Answer the question...why are you scared of typing down a simple yes or no?