"We Are Young," the smash single from Fueled by Ramen act fun. that spent six weeks atop the Billboard Hot 100 earlier this year, hit U.S. digital retailers last September and was supposed to be released in the United Kingdom in early May. But when fun.'s manager Dalton Sim came back from the long Easter weekend in early April, he found a troubling note from a digital representative at Atlantic Records U.K.: Apparently, 18 different versions of "We Are Young" had already popped up on iTunes across the pond. "So the label ended up rush-releasing the single into the iTunes store because of it," Sim says.

The available tracks weren't exactly "We Are Young," but knockoff digital versions of the pop-rock anthem by artists hoping to ride the success of the original. Recently, these covers have begun littering the lower reaches of the iTunes singles chart - a copycat cut of the song by a group named Tonight We Are Young sits at No. 122 on the chart, while fun.'s original clocks in at No. 17. And they're moving a substantial number of downloads. For instance, Carly Rae Jepsen's "Call Me Maybe" single, which tops the Hot 100, this week moved 296,000 downloads, according to SoundScan, while another version by an artist listed as Here's My Number So sold more than 27,000 downloads of an identically named song in the same week. Both songs are listed at $1.29 on iTunes.

For the most part, these covers try to sound exactly like the hit single they're reworking, and the more successful ones use search engine optimization-friendly artist names and song titles to lure unsuspecting consumers looking for the original version into making a song purchase.

"When you listen to the [knockoff], you can tell they're trying to deceive. The voices try to sound similar," says one label source who has investigated the situation. Meanwhile, the artists and labels that release these cover songs often exist as phantoms online. Good luck finding information about the Maroon 5-aping group I'm at a Payphone or its imprint Covered Entertainment on the Web. (A rep for iTunes, which offers a link to these artists, declined to comment for this story.)

Sim believes labels and publishers are becoming increasingly aware of the knockoffs at digital retailers and are keeping vigilant to shut down artists who sample a hit single's master track without permission. But if a knockoff contains all original material, there's nothing that a label can legally do to bar a song from popping up at a digital retailer. After all, Sim says, "You've got groups doing legitimate covers that do amazing worldwide, and that's completely fair game."

The real problem, then, is the dubious listing of these knockoffs on digital platforms. A simple search for "We Are Young" in the iTunes store, for instance, results in fun.'s version showing up as the 24th option. The label source says that iTunes is working to improve its services so that consumers aren't duped into downloading mix-ups, but is also having a hard time from a legal standpoint tagging these covers as "fake." But if original songs and their cover versions were somehow delineated more clearly, sales for the knockoffs would presumably plummet.

"If you could buy the real version for $1.29 versus the cover version [for the same price]," the source says, "I can't think of any good reason you'd want to have the cover version."

The endgame may be the barring of knockoffs from a digital retailer's top singles chart, or perhaps separate search results or charts for "karaoke" versions of popular songs. But Sim predicts that, like illegal downloading services, unauthorized covers will always be a reality.

"I don't sweat it too much. It's going to happen," he says. "In the same way, I don't worry about people stealing music. If they're doing that, hopefully they're talking about it, and hopefully it all comes back to the band eventually."••••