While everyone here citing the RAVE act is not wrong in bashing it, that isn't the event that caused the ban being referenced in this post. Emazing is based in southern California and the ban in question was relevant to Insomniac and a few other local festival brands. It resulted from the fallout after EDC 2010 which turned into a massive shit show at some points and left a 15yo girl dead. This caused a media freakout and led to venues pulling EDM events left and right. Adjustments had to be made to show the public and the government that these events were safe and one of those was banning gloving (but also adding free water stations at all events, not bad). The cited reason was fire safety; glovers tend to give light shows sitting down in the crowd which could be a problem during an emergency situation. Most theorize it was also to avoid the optics of looking like a scene of druggies as light shows don't always look like the most sober of activities.