Virgin Media suffered a DDoS (distributed denial of service) attack on its website at the hands of The Pirate Bay supporters yesterday.
The Virgin Media website was taken down during the DDoS attack, which lasted one hour from 5pm last night.
It is believed that the attack occurred as a protest against the internet service provider (ISP) blocking users' access to the file-sharing website since 2 May, following a High Court order.
A Virgin Media spokesperson said: "Our website, virginmedia.com, has been the subject of denial of service attacks so we took the site offline for a short period of time.
"We're aware some groups are claiming the attacks are a result of the recent High Court order which requires ISPs to prevent access to the Pirate Bay."
It added: "As a responsible ISP, Virgin Media complies with court orders, but we strongly believe that tackling the issue of copyright infringement needs compelling legal alternatives, giving consumers access to great content at the right price, to help change consumer behaviour."
On its Facebook page, The Pirate Bay has released a statement condemning the Virgin Media hack.
"Seems like some random Anonymous groups have run a DDoS campaign against Virgin Media and some other sites," it said.
"We do NOT encourage these actions. We believe in the open and free internets, where anyone can express their views. Even if we strongly disagree with them and even if they hate us.
"So don't fight them using ugly methods. DDoS and blocks are both forms of censorship."
Instead, it suggested, fans of The Pirate Bay should protest by starting a tracker, arranging a manifestation or "teaching friends the art of bittorent".
British Phonographic Industry (BPI), the music industry trade association, asked a group of UK ISPs including Sky, O2, Virgin Media, Everything Everywhere and TalkTalk, to voluntarily block access to The Pirate Bay in November 2011, but the ISPs said they would not comply unless a court order was issued.
The High Court issued the order at the end of last month, requiring all UK ISPs to block access to The Pirate Bay by 11 May.
BT, which was ordered to block access to Newzbin 2 in July 2011 following legal action by the Motion Picture Association (MPA), has requested for more time to deal with the original complaint made by the BPI.