In late October 2010, LimeWire closed down its file sharing services, months after a federal judge sided with the Recording Industry Association of America (RIAA) and found the P2P service liable for copyright infringement. The NPD Group believes this is one of the primary factors responsible for a recent decline in P2P use for pirating music, based on 5,549 January 2011 surveys completed by US consumers.

The percentage of the US Internet population using a P2P file-sharing service to download music fell from a high of 16 percent in Q4 2007 to just 9 percent in Q4 2010, which is when LimeWire ceased its file-sharing operations. The average number of music files downloaded from P2P networks also declined from 35 tracks per person in Q4 2007 to just 18 tracks in Q4 2010. Nevertheless, the number of downloads still range from just one or two tracks to hundreds. NPD estimates there were 28 million P2P users downloading music in Q4 2007, compared to just 16 million in Q4 2010.

Limewire was used by 56 percent of those using P2P services to download music in Q3 2010, but fell to just 32 percent in Q4 2010, since the P2P service was only available through October, according to NPD's Music Acquisition Monitor. At the same time, other P2P service usage rose. FrostWire, a popular alternative to LimeWire, was used by just 10 percent of those sharing music files via P2P in Q3 2010, but this number increased to 21 percent in Q4 2010. The BitTorrent client ĀµTorrent increased from 8 percent usage to 12 percent in the same time period.

"Limewire was so popular for music file trading, and for so long, that its closure has had a powerful and immediate effect on the number of people downloading music files from peer-to-peer services and curtailed the amount being swapped," Russ Crupnick, entertainment industry analyst for NPD, said in a statement. "In the past, we've noted that hard-core peer-to-peer users would quickly move to other Web sites that offered illegal music file sharing. It will be interesting to see if services like FrostWire and BitTorrent take up the slack left by LimeWire, or if peer-to-peer music downloaders instead move on to other modes of acquiring or listening to music."