The website for the WinMX file sharing service has been shut down, suggesting that the service, best known for enabling copyright infringements, has crumbled under legal pressure from the Recording Industry Association of America (RIAA).

Cease and desist letters were sent out last week by the RIAA to seven file sharing services, but the organisation declined to specify which services were targeted.

The RIAA used a July ruling by the US Supreme Court stating that makers of services used for copyright infringements are liable for such violations.

Meanwhile press agency Reuters has suggested that another file sharing network, eDonkey, has been forced to close a New York office listed on its website. 

According to another report, however, the firm moved out of the building last year.

Mark Mulligan, a research director at Jupiter Research, wrote on his blog that the closure of a few services will not stop file sharing. 

"File sharing will get less mainstream in the long term, but it will always be there," he wrote.

"The challenge for the music industry is how to continue to push it to the margins and fill the void with legitimate services.

"If e-Donkey and WinMX do disappear it will be an important victory for the music industry, but it will just be one won battle in the long-term war."