Privatized terms so dominate the public discourse that it is difficult to see or appreciate social evil, communal wrong, states of affairs that implicate us whether we will it or not.... For people who don't believe that there is such a thing as institutional racism, statements alleging oppression sound like personal attacks, declarations of war. They seem to scrape deep from the cultural unconscious some childish feelings of wanting to belong by forever having others as extensions of oneself, of never being told of difference, of not being rent apart by the singularity of others, of the privilege of having the innocence of one's most whimsical likes respected. It is a feeling that many equate with the quintessence of freedom; this powerful fancy, the unconditionality of self-will alone. It is as if no others exist and no consequences redound; it is as if the world were like a mirror, silent and infinitely flat, rather than finite and rippled like a pool of water. -- Patricia Williams, "The Obliging Shell"
I'll be using the word "oppression" in this essay quite a bit to describe the ways in which dominant groups organize -- usually without any conscious intent -- to protect their position as dominant groups, usually making life more difficult for people in less privileged groups (otherwise known as oppressed classes) in the process. "Oppression" may seem like a strong word to people who have never been aware of experiencing it, but I make no apologies for that. Oppression means limiting someone else's choices through coercion; it can take many different forms, not just the violent, governmental ones we're used to thinking of when we hear "oppression", but also ostracism that's perpetuated by informal social structures. Both are about using power to let someone know they're not welcome in a particular space. The effect is to let people know they're not as human as the oppressors are, while also limiting where they can go and what they can do in a concrete way. It's oppression when someone else unfairly makes your life harder because they have the power to do so, rather than because you did anything wrong.
If you're not sure what it means to feel unwelcome in a community, this essay on queer people trying to find a place in a different community (that of people who like video games) might be helpful.
If my use of the word "oppression" makes you feel uncomfortable, or like you're being accused of something you don't think you did, I would encourage you to take some time to reflect on why you feel that way. Rather than blaming me for making you feel uncomfortable -- something that I don't think would be very productive -- ask yourself what combination of feelings and experiences within you is making you feel that way. Many people react to dialogue about oppression by centering their own feelings: they try to shift the discussion from the feelings and experiences of people who experience oppression to how they themselves feel about being called oppressors. Perhaps hearing the word "oppression" -- something they may have believed was reserved for describing past events (like slavery in the United States) or things that people far removed from themselves do (like genocide) -- used to describe behavior they have themselves engaged in makes them feel guilty.