Basically from my understanding the three largest fanclubs banded together to go against SNSD (Cassiopeia - DBSG, ELF - SuJu, SSS - SS501). They were going to band together to support each other and not support SNSD. Anyway, when SNSD's turn to perform came all the fan groups turned off thei glowsticks and were silent, which IMO is fine because at least it's still somewhat respectful, but then I guess later on in the performance they started to yell at the girls to "Disband" and chanted" Plastic Surgery Generation" and were shouting for the Wonder Girls to come on stage. In addition I heard that ELF was dumping water on the SNSD fans below them and tossing water bottles at them >.>
On the flip side (I know I'm in the SNSD forum, but I like to present both sides of the story) it's been said that SNSD fans were the ones that ripped down the two SuJu banners and a Yunho banner. Which may not seem like a big deal, but those things take thousands of dollars to make and time to prepare. So imagine Soshified or whomever, just saying them cause I visit there, spending thousands of dollars on a banner to show their support for SNSD, but then someone comes by and rips it. I saw the fancams of the girls watching it as it was happening, they're crying and screaming, and it's really rather sad. In addition I heard some of the SNSD fanboys punched some of the SuJu and ELF fangirls?
Although now someone else has told me they read somewhere that a DBSK fan stabbed a SNSD fanboy o.O I dunno
However a LOT of this could just be rumors from angry fans so I'm not really sure what is true and what is not.
The only things know that are facts is that banners were torn down, there's fancams to prove it, and that the arena was like almost completely silent during the SNSD performance.
*sigh* I'm a fan of all SM Town groups, so it's really heartbreaking to me to see fans acting like this to each other. People should respect the artists and the people reguardless of everything else. What ever happened to the saying if you don't have something nice to say don't say anything at all? Seriously, if you're not happy with an artist then don't buy their product, but why waste the time and energy to hate on something so passionately? What will you have to show for it later? NOTHING~! It's just wasted time and energy that you could have spent more productively on something else.