Frontliner seems to think so, and Headhunterz played a bootleg that Frontliner made with his track "Never Come Down" blended with Macklemore and Ryan Lewis' "Can't Hold Us" to apparently showcase what he heard when recently hearing "Can't Hold Us" on the radio. Frontliner also posted the bootleg for free:

You can listen to Headhunterz address this on "Hard With Style 25," although he mentions that Frontliner "made good use of the situation" with his blend, and is chuckling the entire time. Maybe Frontliner truly doesn't care. Or it's a joke. Who knows. "Can't Hold Us" was a huge single, battling for the #1 spot with Baauer's "Harlem Shake" earlier this year, so if this is a serious claim, and Frontliner's right, he better lawyer up. And it'd be an interesting dilemma, considering the money Diplo had to pay out to satisfy Baauer's sample clearance woes. In any case, check out Headhunterz' mix starting around the 11-minute mark below to hear the beginning of the bootleg, then Headhunterz comments.

(Be The Rave)