Steak ‘n Shake (a name I will not try to interpret) is suing Burger King over the use of the word steakburger, says the St. Louis Post-Dispatch (one’s range of reading has been somewhat extended by the Internet). Burger King claims it is a generic term (via The Trademark Blog).

bq. Ronald Butters, a Duke linguist, testified that he had found the term in numerous newspaper advertisements by companies other than Steak ‘n Shake going back decades, at least one of them even before the company’s founding in 1934.