Virgin Media has sent about 800 letters to customers warning them that they should not be downloading illegal music files via file-sharing sites.
It is part of a 10-week campaign it is running in conjunction with the BPI to educate users about downloads.
The BPI, the body which represents the UK record industry, told the BBC that thousands more letters would be sent.
Its stricter stance on illegal downloaders might result in some ISPs being taken to court, it told BBC News.
Refuseniks
The BPI wants all UK ISPs to sign up to a so-called Three strikes policy - where users of file sharing networks get two warnings and are then disconnected if they are sharing copyright files.
So far only Virgin Media has officially signed up and it is keen to stress that currently it is running an education-only campaign and that no-one has been thrown off the network.
Virgin Media said the wording on the envelope which contains the warning letter sent to 800 customers - which threatens consumers with disconnection - was a "mistake".
This would be reviewed in mid-August, said a Virgin Media spokesman.
BPI chief executive Geoff Taylor told BBC News that the body was prepared to back up the education campaign with legal action, including taking ISPs to court.
"If we have to go to court, we will go to court and we will win," he said.
One customer who received a letter told BBC Radio 1's Newsbeat programme that he was unhappy with Virgin Media .
Will McGree received a letter in June, warning him that legal action could be taken against him.
He said: "It's doomed to fail. Virgin Media will lose a lot of customers over this because people don't like to be accused of stealing music over their morning coffee.
"It made me feel betrayed. I was under the impression that I paid Virgin Media money to keep my internet connection protected and safe."
He said no-one in his flat had been file-sharing and that it was possible someone had accessed his wireless network from outside the building.
Becky Hogge, executive director of the Open Rights Group, said the letters were a disproportionate response from the music industry.
"We need to protect users from punitive measures," she said.
She said the music industry had to be in a position of offering a viable alternative before it clamped down on the activities of some users.
"Stopping illicit file-sharing might not be as effective a measure as trying to monetise it," she said.
Some ISPs such as Carphone Warehouse, have refused to participate and the BPI did not rule out the possibility of taking such refuseniks to court.
Others, such as BT, have sent letters to subscribers threatening them with disconnection although it said this is not a new policy.
"We have not joined any "crusades", the telco said in a statement.
"We do work with various bodies to help them protect their copyright material and will sometimes pass on warning notices to customers on their behalf where we feel this is appropriate.
If a customer continues to be in breach of our terms and conditions then BT has the right to suspend or terminate that customer's account, though we work closely with customers to avoid this where possible," the statement read.
The industry has been given until spring of next year to find a solution to illegal downloaders or face legislation.
Youth-skewed
The current system involves the BPI policing file sharing networks. It looks for illegal traffic and identifies the IP address from which it has come and informs the ISP .
There is no distinction made between someone who has downloaded one illegal track and someone who has downloaded thousands.
A joint letter from Virgin Media and the BPI is then sent to the individual.
"This is about education. We make no assumptions about who is at fault. It may be someone in the family or someone illegally using their wi-fi connection," said a Virgin Media spokesman.
With conservative estimates suggesting a fifth of Europeans are involved in file sharing, some experts question how much impact such a system can have.
"File sharing is very youth-skewed. The BPI isn't going to close the door on the problem but it can get at the families whose kids are file sharing without their knowledge," said Mark Mulligan, an analsyt with Jupiter Research.
Virgin Media is keen to stress that the 800 or so letters it has so far sent are a drop in the ocean compared to its 3.8m user base.
"In the scheme of things that is a relatively small number," said Ian Fogg, analyst with Jupiter Research.
He said that ISPs faced a difficult balancing act between conforming to the BPI's new rules and pleasing their own customers.
"It is a sensitive issue for providers. File sharers are using up network capacity and therefore pushing up their costs and illegal downloads compete with their own music services," he said.
"They need to be seen to be doing enough so they don't get sued and to control their costs but also need to be careful not to upset their customers."
The record industry has long grappled with how to wrest back control of digital music.
According to Jupiter Research, a fifth of Europeans use file sharing networks. Paid-for digital music services such as iTunes are used by just 10% and make up just 8% of overall music revenue.
The BPI admitted that the current mechanisms for selling music were "broken".
The new strategy will see it negotiating licensed content deals with ISPs who have pursued file sharers.
"We want people to see this not as Three strikes and you're out but Three strikes and you're in to legitimate music services," said Frederico Bolza, head of strategy at SonyBMG.
Some DRM-free material may be made available and the new subscription models will allow users to keep some of the tunes they download, he said.
Geoff Taylor, chief executive of the BPI, said the details of the services were yet to be decided but that there are likely to a variety of models on offer that would be "easy and cheap".
The form they take will be crucial, thinks Mr Mulligan.
"Charging a tenner a month hasn't worked. Ideally it needs to be incredibly cheap or free, with a massive catalogue that can be tranferrable," he said.
Mr Taylor admitted that the BPI's current campaign was unlikely to stop file sharing completely but he did think the idea that the web was home to free stuff needs to be challenged.
"There is a phenomenal amount of piracy out there and we believe that the idea that 95% of content on the net is free is not sustainable. We don't believe that society can allow the free consumption of content to persist," he said.
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
