Thousands of people stripped to their underwear and ran through Salt Lake City to protest what they called the "uptight" laws of Utah, which is full of bullshit laws. Utah is this home of the Mormon church, a vocal opponent of same-sex marriage (amongst many other churches out there. I'm Catholic and the Pope isn't exactly the poster child for equal rights).
Also, Utah recently tightened up its already-ridiculous alcohol laws earlier this month. If you're unfamiliar with Utah's confusing and archaic stance toward alcohol, suffice it to say that when they repealed National Prohibition over three-quarters of a century ago, Utah didn't get the memo. The 'Zion Laws' outlined right here.
It's no ASU run for sure. Ultimately, the promoters main goal of the event was to get the residents and lawmakers in Utah to, 'just loosen up a bit'. That's a message theCHIVERS can get behind.