The Motion Picture Assn., the international arm of the MPAA that protects the interests of Hollywood studios abroad, has won a legal bid in the U.K. to block access to 13 websites that carry pirated movies and TV shows. The blocks will go live in the next few days.

The High Court, citing Britain’s Copyright, Designs and Patents Act, has ordered the country’s five leading Internet service providers to cut off access to the sites, which the MPA alleges are “dedicated to making copyright infringing material available for free on a large scale.”

“This legal process is a well-established, legitimate and proportionate response to illegal websites that make creative content available without permission from rights holders,” the MPA said in a statement.

The sites to be blocked are geektv.is, hdmovie14.net, spacemov.com, hdmovieswatch.net, watchmovie.ms, streamallthis.is, 123movies.to, gowatchseries.biz, themovie4u.com, series-cravings.me, movietubenow.biz, genvideos.org and moviesub.net.

The MPA said research shows that site-blocking is effective. A study from last year “found that, on average, sites in the U.K. lose 75% of their Alexa estimated usage following a site block,” the organization said.

It added that a recent study from Carnegie Mellon University found that former users of blocked sites increased their visits to paid legal streaming sites by 23.6%. It also found that site-blocking caused a 6% increase in visits to paid legal streaming sites, like Netflix, and a 10% increase in videos viewed on legal ad-supported streaming sites like BBC and Channel 5.