Anti- Emo?

There have apparently been Anti-Emo attacks taking place in Mexico. Riot police have taken to the streets of several cities in Mexico to ... defend emo kids? In a Rolling Stone article they discuss anti-emo violence that has started to pop up in Mexico and further south in countries such as Chile. They say, "The first reported instance occurred on March 7th, when 800 young people came to the city of Queretaro with the sole purpose of finding emo kids to beat up" and then say, "A week after the Queretaro incident, a group comprised of punks and rockabillies faced off against the emo crowd". In response "the emo population staged a silent march asking for peace and tolerance through Queretaro’s main center on March 15th. The march was organized by a Mexico City gay-rights organization that feels the anti-emo attacks are fueled by homophobia." Emo and homophobia? I just don't quite understand this world sometimes.

So what is "emo"? When I type in emo to a google search many definitions and pictures pop up. Here are some examples.
Is this emo:


This:


Or this:



I was always under the impression that emo was a musical style and not a fashion statement. I believe that the fashion that is often associated with being "emo" is called "scene". Someone correct me if I'm wrong. If people are being targeted because of their fashion sense, or lack thereof, there is something seriously wrong with people. Not that I have the greatest faith in humanity but it just seems a bit ridiculous to target people for their clothing or musical tastes. No one should be targeted for anything race, gender, fashion, music, whatever...it shouldn't happen...but fashion seems like one of the dumbest things I've ever heard. Apparently the people that are anti-emo don't distinguish between music and fashion, much like everyone else.
On Urbandictionary.com, though not the most credible source it does give some good insight, someone posted a definition (number 6 to be exact) saying, "'Emo' is not short for 'Emotional.' 'Emo' does not mean Taking Back Sunday and Dashboard Confessional, despite what MTV has lead you to believe in the last few years. 'Emo' is not sidebangs, tight pants, and male vocalists who sing like little girls about their failed relationships." Now, as humorous as this sounds there is some validity to it. "Emo" music has become something it was never intended to be.
This poster says, "In the early 90s there was a movement in the hardcore genre that came to be known as "Emotive Hardcore," spearheaded by Rites Of Spring. Harder-core-than-thou kids, who swore by Dischord Records a la Minor Threat, actually coined the term "Emo" as something of a put-down for the kids who really liked Rites Of Spring, Indian Summer and this new wave of "Emotive" Hardcore bands. That's right, "Emo" was once not something kids called themselves." They really hit the nail on the head with that one. Emo was not something that was trendy or anything like that. What it has become is something distorted and is used to reference bands that are, as some have said, shitty pop-rock bands.

So, what is emo and why does it merit violence?

ETA: links to more info http://idolator.com/372899/anti+emo-brutality-in-mexico-it-may-get-worse
http://www.thedailyswarm.com/swarm/update-government-intervenes-mexicos-emo-war-calls-unity/