In Japan people who want to become monks have to sort of run a gauntlet to be admitted, and its become a kind of ritual. An aspirant comes and knocks at the gates requesting admittance, and two or three monks come outside, beat the person up, and run him off. If he comes back, this is repeated. If he comes back more than three times, then he is considered sufficiently serious and is allowed inside. He is given basic instructions concerning how to sit and how to meditate. During periods of zazen the slightest movement may cause the student to get yelled at or beat with a stick. It's kind of silly from my POV, but its more of a cultural thing than anything else. The last Zen retreat I went on more than a decade ago was attended mostly by middle-aged folks who were all deadly serious about practice, yet the Zen teacher treated everyone like kindergartners and yelled at people who made the slightest move. He just happened to have been trained by a hard-core Japanese Zen Master, and that was his idea of good Zen training. I found it very funny. He was causing way more disturbance with his yelling than anyone's slight body movements.
