The High Court has ruled in favour of the government in a judicial review of the Digital Economy Act, launched by two UK broadband providers.
BT and TalkTalk were seeking amendments to the controversial anti-filesharing legislation on grounds of insufficient scrutiny, incompatibility with EU law, and invasion of privacy and freedom of expression rights.
However, Mr Justice Kenneth Parker upheld the principle of taking measures to tackle the unlawful downloading of music, films, books and other copyright material.
The judge rejected the legal challenge, ruling that internet service providers could be made to pay a share of the cost of operating a new mass notification system, but not Ofcom expenses.
A spokesperson for BT told TechRadar that the firm was "disappointed" with the outcome of the judicial review.
"We are reviewing this long and complex judgement. Protecting our customers is our number one priority and we will consider our options once we have fully understood the implications for our customers and businesses," they stated.
"This was always about seeking clarity on certain points of law and we have to consider whether this judgement achieves these aims."