One of my coworkers told two teenage boys that they couldn't use our computers because they didn't have library cards or IDs on them. So what did they do? Snuck on to one of the three computers outside of the computer room. I caught them, called them out on it and proceeded to remove all of the keyboards from the back computers while they were still logged in. One boy looked at the other and he was like "Oh, shit she is gonna beat your ass" I didn't answer, I just pointed to the door.
As a result of me taking the keyboards away, the teens that arrived later on in the day tried to steal the keyboard from our OPAC computer. They though they were being slick tugging on the keyboard wire, but I see everything and they got yelled at.
Basically I spent a good portion of the day yelling at teens. In addition to the computer teens, there was a group of obnoxious girls that I had to keep yelling at because they kept putting their feet all over the chairs and sitting on tables.
Unfortunately I did not win the yelling star for the day, our security guard did. Apparently the Adult Librarians have been having a problem with a book thief. One of the librarians on this fine evening had an idea who it was and he caught the guy in the act, thus our security guard got to scare the shit out of the book thief. Sadly I missed him yelling at the guy. "Favorite Page #3" formally "Favorite Volunteer #1" said she is now afraid of our security guard because he went crazy on the guy.