If they break the law, such as fishing two rods or keeping more than the limits, just report him. If we confront the individual, be careful there. There is always the chance of violence. This has happened at Lafarge a few years back. Crossing line resulted in a shouting match, which then became pushing and punching. Eventually one of the guys fell back and hit the concrete walkway with his head and he died later. What a tragedy.
Violaters or line crossers can be any one. He could be Chinese, Koreans, Singaporeans, Japanese, Vietnamese, Europeans or local whites etc. I have lived in Poco & fished Lafarge for 22 years. I have seen bad examples from all groups. Sometines line crossers have a bad casting skill. Sometimes, it is not intentional. They just can't control the cast as well as others. I have known people who just have trouble casting even after fishing a few years with me. It seems to relate to the motor skill of a person. I usually tell these folks to stay away from the crowded section. Obviously his other Chinese friends don't have this problem. I can understand your frustration because this guy's line crossing is not unintentional. Perhaps we don't even have to mention the nationality or ethnic background in a public forum, because this itself can cause stereotype about a particular nationality or ethnic group even we don't intend to (as you obviously try not to, by declaring your own ethnic background the same as this guy).