The WSJ reports one case has been brought by the former girlfriend of deceased artist Dash Snow, who accuses McDonald's of making him look like a corporate sellout and putting his legacy at risk.
"Nothing is more antithetical to Mr Snow's outsider 'street cred', than association with corporate consumerism - of which McDonald's and its marketing are the epitome," the court complaint said.
Another copyright complaint filed by Los Angeles tattoo artist Eric Rosenbaum wasn't concerned about street cred but money.
According to the WSJ, McDonald's "unauthorised use" of his work strained his reputation and caused him to lose several six-figure licensing deals and contracts.
The complaint was later withdrawn, however. For the Snow case, victory may not come easy.
"Courts and the US Copyright Office have been pretty resistant to the notion that the design of letters is copyrightable," intellectual-property expert Christopher Buccafusco told the paper.