OT: Alcohol sales at Staples/March Madness?

I want to start off by saying last night was an incredible experience, thanks in part to the Staples Center staff and security staff. Also, the overwhelming percentage of Michigan fans (85%+ by my estimation) made it truly sound and feel like a home game. But because the bars were swarmed with the Michigan faithful before the game, it was hard to get a drink. We decided to just bite the bullet and buy overpriced arena beers. But they were not selling any alcohol from what we could tell. They told us it was a March Madness rule. So my question is: is this actually an NCAA rule? Are the other venues selling? I could have sworn back in 2013 in Atlanta they were selling at the game but maybe I’m misremembering. Anyway, just curious if anyone has the answer because I thought it was strange. Still was one of the best days of my life with or without the booze! Go Blue!