This tradition will hopefully stick. It was started in 2011 and works quite simply. The fourth year girl who is the thruster picks three to four guys before the first dance. One or two of the victims must be awkward, and the other two or one should be attractive. This girl then proceeds to do this at the dances: during a non-traditional, non-slow song, she will get a group of her friends to gather around her so she can put on her mask. Then, after this is done, she shall find the first one on her list, go up to them, and pelvic thrust them. However, the girl is not to make contact with the guy(s); she is to merely pelvic thrust and then walk off. She should remove the mask, wait a little bit, and then move onto the second victim during another song. This process continues throughout the entire dance.
The protocol also varies from dance to dance. At the first dance, the thrust should be done from behind this person. For the second dance, she should attempt to do it sideways but may thrust from behind if that proves to be impossible. Finally, for the third dance, the thrust should be done directly in front of the guy. This is mandatory. However, making eye contact with them is not, but it will earn you bonus points. This tradition shall be passed on in secret, on the last night, to the next person. This should be passed onto to a girl, seeing as guys will have no problem doing this.
There is indeed a tangible object that is passed down from one thruster to another, but this object shall remain in secret, as most of the thrusters would like to remain anonymous. There will be people who attempt to copy this, but only one person is the Thruster, and they/their group of friends who encourage them are the only one who know.