Photo by Fabio Venni.

Adam Yauch, aka MCA, was the co-founder and beating progressive heart of the Beastie Boys, who not only made some of the most defining music of the 1980s and ’90s but were among the first celebrities (at least in my memory) to go activist without sacrificing their cool. Yauch, who died today at the criminally tragic age of 47, didn’t just fight for his right to party; he partied for his right to fight.

Most people associate Beastie activism with their vocal support of Tibet, which sprang from Yauch’s Buddhism. But just in case you were looking for another reason to love the man and regret his loss, here’s a less-known story: MCA also used his money and influence to support and distribute a powerful documentary on the water crisis, which pissed off water giant Nestlé so bad that a rep stormed out of a screening — at a film festival Nestlé had paid for.

“She stormed out about an hour in when the film named Nestlé,” said one attendee. “The company obviously had no idea this content was in the movie. She told an audience member, ‘That was one-sided,’ on her way out and didn’t come back for the Q&A session afterwards.”

But Yauch — known for his activism, including helping the Free Tibet movement — makes no apologies. He told Page Six the problem is that Nestlé is “promoting bottled water in general. It’s the bottles themselves, the amount of pollution they create and then disposing of them are problems.

“They put pretty pictures of springs and forests on the bottles, but in this movie they’re getting called out. I think it’s great. They lock down water as a commodity they can buy and sell. It’s terrifying.”

In terms of reasons to miss MCA, that probably doesn’t really rank with things like, say, “No Sleep Till Brooklyn.” It wasn’t even his main activist cause. But it’s another reason to admire Yauch, his commitment to principle, and his willingness to defy convention — whether that convention had to do with music genres, or the expectation that movie producers won’t alienate major companies.

Here’s the trailer for the movie, Flow:

And now, because really all we want to do is listen to Beastie Boy songs for the rest of the day, here’s the first track I played after I saw the news on Twitter. Sorry there’s no real video: