The UK High Court has approved the crackdown on online privacy by rejecting an appeal against the 2010 Digital Rights Act brought by British Internet service providers (ISPs) BT and TalkTalk.

The appeal argued that the legislation breached Internet users’ privacy, and would be ineffective.

The court ruled that the ISPs must curb illegal filesharing by identifying and sending letters to repeat offenders. ISPs will have to pay a quarter of the costs of sending warning letters to offenders, while the rights owner will pay the rest.

However the court allowed the ISPs to not contribute to the regulator Ofcom’s costs in setting up the system and establishing an appeals body.

Justice Kenneth Parker dismissed the ISPs’ claims, saying, "from the point of view of both copyright owner and subscriber, the DEA [Digital Economy Act] represents a more efficient, focused and fair system than the current arrangements."

"The DEA proceeds on the premise, first, that a significant number of infringers do not at the moment fully appreciate that what they are doing seriously infringes the legal and moral rights of others and that, although individual behaviour of this kind may seem trivial and excusable, the general effect may well be very damaging to the creative industries, a notorious example of what is sometimes called the tyranny of small decisions that have ruinous economic consequences," he said.

"Although it is difficult to predict the effect of measures such as those contemplated by the DEA, there are reasons for believing that such measures may well have positive effect."

The Department for Culture, Media and Sport said it was pleased that the court has recognised the measures as both lawful and proportionate.

It added, "The government remains committed to tackling online piracy and so will set out the next steps for implementation of the Digital Economy Act shortly."

Rights holders including The Premier League, The Motion Picture Association and recording industry group BPI welcomed the ruling.

BPI chief executive Geoff Taylor said, "This judgment gives the green light for action to tackle illegal downloading in the UK."