First of all, let's define what the word hipster means and where does it come from: to my understanding, the word virtually means "fashion chaser" (hip or hep were terms used in the 40s in the Jazz circles to describe something hot and new), and it was used to describe the beatnik kids that were trying to emulate the Beat generation in a very superficial way, completely oblivious of any intellectual depth and cultural meaning. In my opinion, the post-war generation of the atomic era had a severe identity crisis.
The above paragraph describes also what "poser" means, though this term became more popular in the 80s and 90s. They never really disappeared, they just remained around being hippies (derived from hipster), or became attached to any number of subcultures in a desperate attempt to find a sense of belonging, and in turn, after a period of time, the mainstream assimilated part of this subcultures through these hipster filters.
It was up to this century that the hipsters took off as a culture by themselves. To my knowledge, thanks to two factors: kids born in the late eighties and early nineties that grew up immerse in stuff like Barney and Happy Meals; and the internet, that made a lot of stuff very accessible without any effort for their entire life. This, in turn, created the stupidly immense identity void the world has to deal with now. Why? Because this generation was brought up to believe everything is worthless, meaningless, and transitory (don't be a wise-ass associating this to the cosmological fact), take that bravado, and put it in the middle of the fastest changing cultural and social paradigms any civilization has ever faced, and you get a bunch of morons that celebrate themselves while stealing ideas from other types of people (like the ugly looking big specs or the 80s tight pants) because they are mostly just mindless consumers incapable of original thinking that need to be embraced and accepted by their peers. Some even think this trends, the music... are something original, while in fact, anyone older knows that they are just stealing 80s synth-pop and the tired chord patterns of the Velvet Underground that have been a constant in music since the 70s. Plus, they don't mind mutilating the message, the scene, the concepts, why? because it came very easy to them, they literally only had to move a finger, downloads are one click away.
I remember being a fanboy since an early age, obsessed with comic books and music, the difference is that there was no internet and the other communication facilities we have today, so, trips to the library, spending hours in bookstores, magazine stands and record stores was quite common, and some stuff was basically unattainable, to get like, demo tapes or b-sides and stuff, you basically had know the band personally. And to get Wednesday comics in Mexico City? It was hell, you had to hunt down the issues through all the stores that carried american magazine publications, and there never was any sense of order. Not to mention, none of this was cheap. You basically bought 1% of the stuff you wanted. TV and movies? They took forever to come (if they actually were broadcasted here), and there was always the factor that they were edited, or filled with commercials. If you liked a song, well, you listened to the whole album, as the artist intended, not to mention that in most cases you had to pay for them, unlike now that people claim to like a band but only have like one mp3 of said music talent, and they got it for free.
That's why I get mad when hipster kids tell me they like comics because the downloaded Watchmen (and probably didn't get much out of it, since they aren't accustomed to reading comics or understanding their context and background), or when they regurgitate the Wikipedia article of some band, when they haven't even listened to more than a couple of songs by them. I'm not saying it is mandatory to be passionate about this things, but don't claim to be a nerd and hijack the scene, when you have no fucking clue whatsoever, not even of who you are as an individual, let alone culturally. Don't tell me you are the art vanguard when all you do, is just a re-fried version of stuff older than yourself, or consider yourself an informed critic when you still think the Beatles are a groundbreaking act (they were, 50 years ago). Just because this kids don't have a clue, it doesn't make it right to treat what some of us do love and have invested time, money, effort, and our hearts into, like a cheap whore.
This kids have interesting behavior patterns (beyond auto-celebrating every stupid, tired "ideas" they "come up" with). For example, it appears that calling a hipster "hipster", is an insult, kind of like calling Tony Hawk a "skater" in a derogatory fashion (if that is actually possible), what's so hard about accepting you are a hipster? And funny enough, they see themselves as misunderstood geeks, thinking geek means nerd, when geek was actually intended to be a derogatory term, and not really for intellectual types, but for the smelly, booger-eating freaks that lurk around high-school, the term comes directly from the freakshow geeks, that ripped off chicken heads with their mouths. There is also the "art" factor, no one has ever really defined art, except for them. apparently. They all take photographs (or is it the camera that does that?), they are all music-savant DJs (apparently, pushing buttons on a console is art), produce and enjoy mind-numbingly slow, plotless, derivative, unexciting movies (that would work better as photographs), but in no case you will find them pushing the envelope, perfecting their craftmanship (that's too pretentious, and trust me, these people KNOW pretentious).
In conclusion: Most kids today seem to be hipsters (even if they don't want to acknowledge it) that ruin everything for everyone else and don't have respect for anything other than their own egos, even though ironically enough, most lack a personality of their own. By the way, I found this fun poster you can enjoy, even if I don't exactly concur with the Emo part.