It tends to be a fruitless digression into semantics in any case, but the broad strokes of what I believe Oluseyi is getting at over the application of the word racism is that usually institutionalized discrimination towards a race is simply called racism, if somewhat colloquially. Institutions (businesses, ideological parties, law enforcement departments) are bigger than individuals and more able to unfairly discriminate -- one upset white guy isn't as powerful as 20, or 2000, or 2 million -- in fact, the power the institutions wield has the effect of creating not only deleterious conditions for those they target, but also beneficial conditions for those who are unlike them. This is what a lot of people are calling "privilege" in the media today. Long story short, even if you yourself are not actively discriminating, its likely that you're benefiting from the "privilege" that arises out of the disparity that institutionalized racism creates. What's more, because you receive these benefits detached from any wrong-doing, its hard for most people to identify them as part of a playing field that has been tipped in their favor -- and equally out of favor for others. Unconsciously, people who benefit from this system will reinforce it as rational (that is, self-interested) actors, unless and until they begin to understand and value the experience of those on the other side of the field.
To head off one argument before it begins, no one is saying that those with privilege should not accept its benefits (though, I would argue that those who actively bend it to their favor at the expense of other's are sociopaths supreme), but that we should try to see them not as benefits to us, but as penalties for those who do not experience them as benefits. The goal is not to remove privilege, it is to remove penalty.