Originally I was going to write a post on the soundness of the "white privilege" argument. However, lately I've been interested in rhetoric so I'll discuss it from that angle. I've decided that the term is an insidiously brilliant rhetorical device that is non-debatable in some circumstances.
In most cases I've seen the term debated on the web a person brings up the soundness of the white privilege argument and the white privilege theorist claims it is true because he can see it.
Debater 1: I can't see white privilege around me because of claims a, b, and c. Therefore white privilege doesn't exist.
White Privilege Theorist: That's because you can't see claims x, y, and z. Hence you can't see white privilege. It is an "invisible knapsack." Also, if you can't see it then it is likely you are an individual who has white privilege. I can see the "invisible knapsack" therefore only I can evaluate the concept of white privilege.
From here Debater 1's race is often called into question, as the white privilege theorist brought up above by claiming Debater 1 cannot see white privilege (because -- presumably -- he is white).
White Privilege Theorist: If you cannot see it then I assume you are white?
Debater 1: Yes.
The White Privilege Theorist proceeds to evaluate Debater 1s argument based on Debater 1s race and his alleged inability to perceive the "invisible knapsack", not on the truth or validity of the claims that Debater 1 may bring to the argument (in fact Debater 1s argument is meaningless to the White Privilege Theorist anyway because the debater cannot see the "invisible knapsack").
Or in simpler terms it is cheap rhetoric, not sound argument.