Guidelines:
1. Say what was the stupid rule and how it failed, don't spare details!
2. Have fun!

And now it's time for honorable mentions!

Miss Ann Thrope:
We had to participate in the D.A.R.E. program. A police officer visited our class once or twice a week to promote America's war against drugs. Years later, studies showed that the whole program was a spectacular failure worldwide.


WaitandSee:
My High School had quite strict internet traffic filtering which blocked access to a massive number of websites, it used key-word filtering, phrase weighting and blacklists, since majority of the school was issued Macbooks thanks to a Government Initiative, people would often be using them for recreational use during breaks or in class (When they should be working), an Infamous system called DansGuardian.

I managed to get the DET's (Department of Education and Training) Proxy Details through less than scrupulous means (Watching over a staff member's shoulder while typing) and some of my colleagues managed to use the single biggest weakness in any IT Security system, Social Engineering, they needed access to a specific website to get data for an assignment, this website was blocked by DansGuardian, so they managed to get the member of staff to put in the Proxy address and password to bypass it, they obviously recorded the address and the password for the proxy and voila, we now have a proxy that bypasses the DansGuardian.

It was about a year maybe that we had this proxy but someone leaked it, then it started spreading (Loose lips sink ships), they promptly changed the proxy after finding out Students had access to it.

I then switched to using a VPN to encrypt my traffic, sending data over port 80 and port 443, Immunity Gained, can't filter HTTP and HTTPS ports now can you? Hehe.

Mutant Strain:
Well in my senior year they made a rule that no one could leave school grounds during the day and they locked all the gates from start to finish and there was a massive protest and almost everyone just walked out of the school. They didn't take away the rules though but we found ways around it I mean as if it's that hard to dig a hole under a fence, we were like a bunch of rats escaping from prison.

RetroCat:
The zero tolerance policy. It basically ensured that bullies got absolutely no punishment for their actions while the victims that stood up for themselves got punished along with their abusers. What's the point? Lip service the lot of it.

That's all folks, but remember! If you want to get an honorable mention or just help out this post out in general, type in a dumb rule that backfired beautifully! Until next time!