UK internet service providers have been asked to block access to dozens of URLs that are suspected of linking to pirated content.
Content providers regularly update the lists of sites they want blocked and the latest one includes popular file-sharing index Demonoid.
The list was started in 2012 when ISPs were forced to block access to the Pirate Bay.
At least 23 new URLs are on the latest list being sent to the main UK ISPs.
Content providers must apply for a court order to block individual sites such as Pirate Bay but, after that, they can add URLs that link to that particular site without any formal order.
The sites they choose link to pirated software including music, films, TV shows and e-books.
Content providers say that they carefully target sites whose sole purpose is to make money from other people’s content.
In response to the latest requests, BT told the BBC: “BT will only block access to websites engaged in copyright or trademark infringement when ordered by a court to do so. The list of websites that BT has been ordered to block access to can be found here.”
The list includes content from the Football Association, the Motion Picture Association of America and even some watchmakers – such as Cartier and Montblanc – who have requested that counterfeit sites be shut down.
But by far the largest number of requests comes from members of the BPI, which represents UK music labels.
“The recent expansions show that copyright holders remain concerned about people circumventing blockades, which is a common practice among users,” said Ernesto Van der Sar, editor of technology news website TorrentFreak.
“New unblocking opportunities continue to appear so this is the only way to ensure that the efficacy of existing court orders isn’t further diminished. It’s a never-ending game of whack-a-mole.”
How effective such blocks are remains open to debate.
A study conducted in May, by US universities Carnegie Mellon and Wellesley College, found that blocking the Pirate Bay had little impact on the rise in legal channels – instead people just turned to other piracy sites, Pirate Bay mirror sites or virtual private networks that allowed them to circumvent the block.
But, on the other hand, researchers found that bulk blocking – where multiple sites are shut down – was much more effective. Following such blocks in 2013, use of legitimate sites such as Netflix rose by around 12%, they found.