Back in the day when I first started getting a bazillion usernames various places online, you could get almost anything. That was nice. A bit later, they started running out of normal ones, so people would choose things like xXMoRoNXx and ~*~H00ChiE88~*~ and 69IGN0RME69 and the like.
Now I run across an insane number of usernames, particularly on LJ, that are some variation on a ton of underscores and then a random "deep" word. As if ________chimera, or even better, __________apathy somehow symbolizes that they are flatlining from the pure emo-ness of their life. They are cooler than you, because they have one word in their username and they like Death Cab for Cutie and The Postal Service, only they refer to them as dcfc and tps. Only people with good eyesight are allowed to read their journal, because it's all in a 7 point font, just like their userinfo, which often has a dramatic & slightly blurry (or, less often, high contrast) photo of them. And they want you to remember that they are cooler than you, even as they call themselves dorks and losers.