The smartphone revolution is changing the music piracy landscape at a rapid pace. New research by market research firm NPD concludes that downloading unauthorized music via mobiles has outgrown traditional online piracy sources such as torrent sites and cyberlockers.

In recent years the music industry ‘s battle against piracy mostly focused on torrent sites, cyberlockers and unauthorized MP3 indexes. However, new research from the industry analysis firm NPD Group suggests that a new, much bigger threat, has arrived.

NPD’s Senior Vice President, Industry Analysis, Russ Crupnick informs us that mobile music piracy through apps has outgrown traditional P2P file-sharing and direct downloads.

“In terms of the number of internet users doing a variety of music sharing activities, downloading from mobile apps is the most popular,” Crupnick tells TF.

The data comes from unpublished research, which was the first to include statistics on the usage of mobile apps to download music. Quite surprisingly, mobile piracy comes out on top right away.

It is estimated that in the United States 27 million people downloaded at least one music track via their mobile over the past year, mostly without permission. This trumps all other forms of online piracy. By comparison, 21 million people used traditional P2P sites such as The Pirate Bay to download music.

For other media types the results are different, but the findings signal an interesting trend.

According to NPD mobile apps are, as one would expect, most popular with younger consumers. There are a variety of reasons for the mobile piracy explosion, but the research firm believes that increased usage of smartphones and apps among Millennials is a major driver.

“My guess is there is an underground buzz network about music apps that is fueled by teens and Millennials,” Crupnick says.

NPD believes that it’s important for copyright holders and app platforms to work together to tackle this problem. While some people may know that these apps are unauthorized, the fact that they appear in iTunes or Google Play may give them an air of legitimacy.

“Lots of things on the web are free or ad-supported, including some entertainment content. I’m sure some users are quite aware that there is music that is not legally distributed on these apps, but others may not be as educated,” Crupnick tells us.

“If it’s on an app store, it must be ‘OK’. This is where the music industry and technology companies have an opportunity and maybe an obligation to work together to make sure consumers understand, and artists get compensated,” he adds.

These last comments appear to signal a new working territory for the music industry’s anti-piracy initiatives. Until now, there hasn’t been a major campaign against “infringing” apps, but this is bound to change in the near future.

Whether a crackdown on apps will be enough to counter the current mobile piracy trend has yet to be seen. In addition to pirate apps, several unauthorized MP3 indexes have also developed mobile versions, which will prove much harder to deal with.