By Finlo Rohrer BBC News Online entertainment staff

A war is being fought between record company bosses and computer users for the future of music.

As compact disc sales slide, previously bland industry events have started to provide pulpits for industry figures to launch increasingly strident attacks on the websites that could soon deprive them of a livelihood.

The latest figures from the Recording Industry Association of America (RIAA) point to a 7% decline in CD shipments to record stores - which they say closely matches sales - and polls of computer-using music fans to decide that the internet is killing music.

You can't compete with music for free Adrian Strain IFPI

The International Federation of the Phonographic Industry says billions are being lost in copied CDs, but the damage from the internet is unquantifiably vast.

Communications director Adrian Strain said: "Physical piracy costs the record industry over $4bn. We don't put an estimate on the value of the internet pirate market because there isn't a very large online legitimate market."

But he estimated the lost sales were in the hundreds of million.

And there is a sharp international divide, with street markets full of counterfeit CDs a common sight from Shanghai to South America.

"In the southern hemisphere it is commercial, organised criminal-based piracy, in the developed world it is more a question of the internet," Mr Strain asserted.

Napster battle

Artists as diverse as Jean Michel Jarre, Eminem and Metallica drummer Lars Ulrich have vented their spleen on the topic of music "piracy", blaming it for reducing CD sales.

Ulrich's target was Napster, the music file-sharing service that became a martyr after legal challenges helped neuter it. But like the Hydra, a thousand file-sharing sites jumped up to replace it.

Only last week a site in China was shut down amid legal action against internet service providers (ISPs), but San Francisco's Electronic Frontier Foundation has dubbed the tactics of trying to stop piracy through the fabric of the internet as "whack-a-mole".

Jean Michel Jarre recently spoke out

And things are about to get tougher if US politician Howard Berman gets his way. The politician wants copyright holders to get near immunity from the law for hacking attacks on computers that they suspect are being used for file sharing.

The EFF insists: "Exempting a single industry from civil and criminal penalties is unprecedented. This kind of vigilantism is explicitly prohibited by law."

The organisation's lawyers say they do not want a futile fight against piracy to affect civil liberties.

There are also rumblings in the industry about suing or even prosecuting individual users sitting in their bedrooms, a tactic that RIAA president Cary Sherman refuses to rule out.

Education battle

"It is difficult to have sympathy for someone who willingly uploads massive amounts of copyright material."

But he recognises the industry faces a battle to win over the hearts of the ordinary consumers and voters, particularly when the pop stars delivering the message are rich beyond their wildest dreams.

"We need to do a bit more to win the battle for hearts and minds. I don't think as an industry we have done enough to educate people that it hurts musicians and that real fans don't steal. When they do musicians pay.

The record industry is the venture capital firm of music - it is making a highly risky investment where no-one else will Cary Sherman RIAA

"We need to focus on the up-and-coming artists not people who have already succeeded. They are the ones who are not getting promotional and marketing budgets. They are the ones who are going to be suffering from the pirating of Eminem."

The industry's concern is understandable. If it has no money to spend on radio pluggers, advertising, studio space, star producers and other promotions, it has no industry.

But the counter-argument can be heard in any pub. Ordinary music fans want to know why in the UK, you can still be charged �16 for a CD, when the industry is trying to stop listeners heading for internet.

Mr Strain is adamant cutting prices will not help fight piracy, insisting: "There is no connection between the cost of CDs and music and piracy. You can't compete with music for free."

On the other hand, Mr Sherman says he supports the "experimental pricing" currently visible in America, but insists CDs still represent "tremendous value".

Eminem's recent album had anti-piracy technology

And the record industry is equally defiant about its sudden conversion to champions of the artists. After years of accusations ranging from sharp practice to outright theft of artists' copyrights in the 1950s and 1960s, bosses are adamant their house is in order.

Mr Sherman argues: "The record industry had its share of Wild West entrepreneurs back in the early days but that is ancient history. The record industry is very legitimate and it is unbelievably profitable to the artists that succeed in this system.

"The economics of the record business is difficult to explain. The record industry is the venture capital firm of music. It is making a highly risky investment where no-one else will."

One thing record industry lobbyists on both sides of the Atlantic are sure of is that there will be "less investment in new artists and new music".