Assuming

The problem with the internet is that you can be whoever or whatever you want to. With no way to validate another's identity on the web you must use your intuition to decide if you can trust people as to who they are. Unless you know and have met this person in person there is no way to know if the person you are talking to is who they say they are (example the movie and now tv series catfish). This has happened many times, including the mess when it was discovered that some of the editors of Wikipedia were not experts as they had claimed, but just regular people.

Now the problem with not knowing very much about the people that you converse with online is that you end up assuming a lot about this person. When I was younger I used to play an online game, something similar to a MMORPG. I made online friends, and because I had never met them in real life I assumed almost everything about them outside of our interaction in the game. As we became better friends we started talking outside of the game. For example I became friends with them on Facebook and MSN. I found out that al of them were completely different than I had imagined them being. Finding out more about people outside of the game always changed the relationship inside of it.

Another aspect to this is that I found out that people would fake an online identity to take advantage of people within the community. For example a significant number of people from my school also played the game. Now as you can imagine this online community was comprised of mostly males with a very small female population. A guy from my school told me that he was going to create a profile and pretend that he was a girl. He was going to do this to get other players to gift him premium items that required real world money.

I don't believe that the internet creates an assumption that everyone is a white male. I believe that the internet causes us to see people as we imagine them to be, and we almost always see them as being at the extremes. We need to remember that people online are just like you and me, and it is not fair to hold them to such extreme standards.