Today, I witnessed a nice birthday bumps of a friend of mine in really close quarters...Involved quite a lot of things that could come under the human rights violation acts...
So here is the wiki topic on Birthday bumps:
Punches, pulls, and "the Bumps"
One widespread birthday custom takes many forms around the world, all rooted in the idea of delivering some form of physical torment to the person whose birthday it is, in order to drive away evil and to attract good luck. These torments range from beatings, through punches and earlobe-pulling, to "the Bumps".
"The Bumps", a torment common in countries such as the U.K., Ireland, and the U.S., involves the friends and family of the person whose birthday it is taking him or her by the arms and legs, and "bumping" him/her up into the air and down onto the floor. The number of "bumps" given equals the age of the person in years plus one "for luck". Usually "the Bumps" are administered only to children, in part because as people grow up they become too heavy for the process.
In Francophone Canada and the U.S. "birthday punches" are given in a similar fashion, where the person whose birthday it is is punched a number of times equal to his/her age, plus one for luck. In Brazil, Hugary, Argentina, Italy, and other countries, the person has his/her earlobes pulled. The Hungarian tradition also involves at the same time as pulling the earlobes wishing the person a happy birthday or reciting a rhyme whose English translation is "God bless you, live so long so your ears reach your ankles.".
In Israel, part of the birthday celebration for a child in kindergarten is to lift the decorated chair that the child sits on into the air several times, once for each year of the child's age, plus "one for the next year".