Is it illegal to download "pornographic" content via BT?

Ren Chaoqi, a resident of Nanyang, Henan, has been very upset recently. On the day after his wedding, his computer was suddenly searched by local cyber police. A 30-minute "yellow movie" (traditionally known as "obscene video") he had downloaded from the Internet using BT resulted in a fine of 1900 yuan. The case sparked a flood of discussions online, and a Nanyang cyber policeman with the ID "Feverish Wind" even publicly debated with netizens. I originally thought that the principles explained by some netizens would be sufficient to clarify the matter, but after carefully reviewing the entire process of the case, I realized that the Ren Chaoqi case was not as simple as everyone had said...