I realize you may just be venting but consider complaining to your college administration either via your student council or by yourself.
It should not be the norm to have to tell a stranger where you are to eat food.
You are paying for your education even if you are doing so via a loan and that gives you the right to tell them how you feel about them invading your privacy. In college and in jobs authority figures routinely try to control you and it is worth learning to take a stand against such abuses.