O2 has slammed a UK law firm for issuing letters to web users suspected of illegal file-sharing, saying they "bully or threaten" consumers.
In January, it was revealed that ACS:Law had issued letters to around 150 Brits, claiming they had illegally downloaded content from the web.
ACS:Law said it was acting on behalf of DigiProtect, an anti-piracy firm that represents a number of copyright holders, and the recipient was required to pay a £500 fine and sign a legal undertaking agreeing not to illegally file-share in the future.
O2 said it was "legally obliged" to provide the law firm with contact details for a number of its customers after IP addresses belonging to the ISP were identified as having taken part in illegal file-sharing.
The mobile network said it preferred the "win-win approach of encouraging the development of new business models that offer customers the content they want, how they want it, for a fair price".
However, Andrew Crossley of ACS: Law said the letters did not bully or threaten anyone.