Dominic Engels, Stone Brewing's CEO, said the cans are "aggressively deceptive advertising."
"Keystone's rebranding is no accident. MillerCoors tried to register our name years ago and was rejected. Now its marketing team is making 30-pack boxes stacked high with nothing but the word 'STONE' visible," Engels said in a release. "We will not stand for this kind of overtly and aggressively deceptive advertising.
In a YouTube video posted Monday, Greg Koch, Stone's executive chairman and co-founder, said the craft beer heritage they have developed is being threatened by "big beer."
"We believe that MillerCoors is intentionally and deliberately trying to create confusion in the marketplace in their Keystone brand," Koch said. "You can see very clearly they are just trying to line this up and push the word 'Stone.'
"Hey, in the world of beer the name 'Stone' is ours."
In the video, Koch, who is no stranger to bashing "big beer," holds up a can of Keystone Light before joking it featured "two words that you would never see together in association with our company" and performing a spit-take.
In a statement to 10News, MillerCoors called Stone's lawsuit a "clever publicity stunt."
“This lawsuit is a clever publicity stunt with a multi-camera, tightly-scripted video featuring Stone’s founder Greg Koch. Since Keystone’s debut in 1989, prior to the founding of Stone Brewing in 1996, our consumers have commonly used ‘Stone’ to refer to the Keystone brand and we will let the facts speak for themselves in the legal process.”
MillerCoors owns more than 50 beer and alcoholic beverage brands, including San Diego-based brewery Saint Archer.