When we begin with facts and based on the facts presented we draw a conclusion, this is fair comment based on facts. Even if the comment is pointing at a person, it is a fair comment on the person and not a personal attack.
However, if the “facts” are not facts but only an isolated statement focusing on a certain topic made generalized, then the conclusion is not valid. What is worse is that sometimes the conclusion may be personal and it becomes personal attack.
For example, this is what I wrote:
“What are the numbers at the central palace then? If you look at them just as numbers, of course you will not get the answer. The time star there defines the "Heaven's Heart". It was the ruler of the time when the house was built. It dictates the way basic qi coming from the 8 directions. In Feng Shui, we focus at directions, not location. For people who understand, this is no secret. For people who don't, this is a secret they can never get.”
The topic of discourse was restricted to examining the flying star chart of a house. It explains how to read the stars in the nine palaces. You cannot isolate one statement in the paragraph to generalize it for situations other than this. If you do, the conclusion is not valid. If the conclusion is to attack the author, it is personal attack. This exactly what Compass Chung did in his article. Read his conclusion:
“By carry out services based on Joseph Yu's statement, they may endanger other people's live;not to mention that they are teaching this principle and spreading the poisonous gas to the public.”
This is the most vicious personal attack.
He wrote such an article is a fact. My conclusion based on what he wrote is:
(1) Either the understanding ability of this young man is too low or
(2) He purposely twists the idea in the paragraph to suit his purpose.
This is what we call a fair comment based on facts and is not a personal attack.