Wikipedia doesn't make them sound so bad - "three central tenets of the belief are Truthfulness (真, Zhēn), Compassion (善, Shàn), and Forbearance"

The troubles seem to stem from "April 1999, when over 10,000 Falun Gong practitioners gathered peacefully near the central government compound in Beijing to request legal recognition and freedom from state interference."

I guess peaceful demonstrations against the state are going to get you tiananmen squared over there.