Our school had the "Little Store", where kids could buy soda, snacks, candy, etc. It was a revenue generator for the school, and the various clubs and orgs ran fund-raisers out of there.
There was no school-wide ban on transporting and eating these snacks. It was assumed that since we used our own money, what we purchased in the store was our business. If a particular teacher didn't want food or drink in class, they would say so, and it was expected that their wishes would be respected.
I made the mistake of taking an "interpersonal communications" class because a hot chick told me it was easy and that I should take it. The teacher and I did not hit it off, to say the least. He hated me for some reason I never knew, and that just encouraged me to show him disrespect every chance I got.
One day per week we'd have a large-group lecture class where all the IPC classes would meet at the same time, and the different teachers would rotate. It was always understood that the large group lecture classes were OK for snacks. I brought Peanut M&Ms on a day Mr. Charpentier lectured, and for whatever reason, he singled me out and chose to make some kind of authoritarian example of me. He told me to give him the M&Ms. I said no, I paid for them. If you want me to put them away until after class, I'll put them in my binder, which I then proceeded to do.
He began walking quickly towards me, yelling, "I told you to give them to me!" I laughed and refused, and reiterated - I put them away, it's not going to be a problem, I won't eat any more, it's never been a problem before, but you're the teacher, if you don't want me to eat them I won't, but I'm not giving them to you.
He actually approached me, grabbed my shirt, and lifted me out of my chair, screaming, "I told you to give me the candy!" Alarmed at being manhandled, I grabbed him right back, so we had one another in both fists by the shirt-collar. I was bigger than him.
He screamed, "You're coming to the office with me!" I screamed back at him, "No, YOU'RE coming to the office with ME!" And we proceeded to haul each other down to the vice-principle's office.
We burst in (the VP and I were on a first name basis, not in a good way), and I told the VP, "This guys giving me sh*t! He's trying to take my candy that I paid for, when all he had to do was ask me to put it away. It was never a rule until today!" I was yelling at the top of my lungs.
The VP said to the teacher, "Don? How about you head back to class and let me and IDP work this out." He said to me, "I think you'd better take the rest of the day off and calm down." My buddies and I left for the rest of the day. (It was easy for them to skip out because with the Mod Scheduling, unless you had a scheduled class, there was no accounting for your whereabouts.)
When I returned to class the next day, I was no longer in Mr. Charpentier's class. I was transferred to another class, and I got along with the teacher just fine.