If you can't beat 'em, might as well join 'em. Which seems to be the idea behind Warner Bros. Records' curious tie-in to Green Day's new album, American Idiot: a five-pack of blank CD-Rs emblazoned with artwork for each of Green Day's major-label albums ($7.99 at greendaymusic.com). In an industry still fighting illegal downloading and CD burning, is offering blank discs as good as aiding and abetting the enemy? Calling the set a ''collectible for fans who buy music digitally,'' Robin Bechtel, head of new media for the label, thinks not. ''It's so if you download a Green Day album from iTunes or another digital retailer, you'll have something unique to burn the music on.'' Fine, but who's to say we won't burn the new Lionel Richie album instead? Now that's punk!