Virgin Media sent 800 UK customers letters warning them about participating in illegal file sharing.
The letters are part of a 10-week campaign, in conjunction with music industry body the BPI, in a bid to 'educate users' about illegal downloading.
The BPI has been urging ISPs to implement a 'three strikes and you're out' rule for illegal downloaders which would see offenders first issued with written warnings. If they continue to illegally file share, offenders will then see their internet access terminated. However, Virgin Media is the only ISP so far to start implementing the policy. Although it highlighted that the letters represent an education-only campaign and that as of yet no-one has been disconnected from the internet.
"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.
However, a number of customers who have received letters have complained that the letters have been strongly worded, threatening possible legal action. Virgin Media said that wording was a "mistake".
The government has given ISPs until next spring to stop illegal file sharers themselves, otherwise legislation will be brought in that forces them to punish offenders.
Some ISPs including the Carphone Warehouse, however, have refused to participate and have been threatened with legal action by the BPI.