Six years after massive online protests shuttered wide swaths of the internet, the music industry has renewed calls for internet filters in a bid to tackle copyright infringement. But experts say such filters not only don’t work, they tend to result in unintended censorship, a lesson the industry refuses to learn after years of controversy.

Both the Stop Online Piracy Act (SOPA) and PROTECT IP Act (PIPA) were laws proposed by the entertainment industry that would have forced ISPs to censor websites deemed infringing by the entertainment industry. A massive online backlash ultimately scuttled both proposals in 2012 after thousands of companies, artists, and critics argued the filters would chill legitimate speech and potentially break the internet. It’s not clear that the entertainment industry has learned much from the experience.

Last week, both the Recording Industry Of America (RIAA) and the National Music Publishers’ Association (NMPA) sent their latest recommendations for copyright enforcement “improvements” to the US government’s Intellectual Property Enforcement Coordinator (IPEC) Vishal Amin, who had put out a call for industry feedback.

“There are several changes that should be made legislatively to help legal authorities and third parties better protect intellectual property rights,” the music groups said in their letters to the government, first spotted by Torrent Freak.

“These include fixing the [Digital Millennium Copyright Act], making it a felony to knowingly engage in unauthorized streaming of copyrighted works, and investigating the positive impact that website blocking of foreign sites has in other jurisdictions and whether U.S. law should be revised accordingly,” the entertainment industry argued.

The groups went on to insist that "as website blocking has had a positive impact in other countries without significant unintended consequences, the US should reconsider adding this to its anti-piracy tool box.” But numerous copyright experts told Motherboard that “unintended consequences” are a frequent occurrence. Homeland Security accidentally shuttered 84,000 innocent sites in one 2011 copyright enforcement effort, and Australian filtering efforts resulted in more than 250,000 non-infringing websites being unfairly targeted and temporarily taken offline. Experts say imposing domain-level blacklists of infringing sites is similarly problematic, since such filters are usually easily bypassed with only a modicum of technical know how. “DNS blocks are easy to circumvent, because site operators can just register a different domain name in the same top level domain or move to a different top level domain,” Annemarie Bridy, Professor of Law at the University of Idaho told Motherboard. “It will always be a game of cat-and-mouse, with no real permanent effects.” Bridy noted that when countries apply such systems at scale with little recourse for the unfairly targeted, “the negative externalities for legitimate expression are potentially huge,” adding that a lobbying organization focused on revenue generation shouldn’t be dictating essential core internet policy anyway.

“The RIAA has an obvious interest in selling site-blocking to policy makers,” Bridy said. “They’ve historically been dismissive of adverse effects on other people’s speech. Of course, it’s in the RIAA’s interest to exaggerate the benefits of site-blocking and to downplay the costs. That’s what we’d expect them to do as lobbyists for the music industry, and that’s what they do.” Other copyright experts told Motherboard that the best solution for copyright infringement is the development of better, legal alternatives to piracy. New laws mandating ISP website filtering will “only incentivize bad actors to find new avenues to disseminate infringing content,” Sasha Moss, copyright expert and Federal Affairs Manager at the R Street Institute told Motherboard. “The only way to combat piracy is to create legal and accessible options for sharing content online.” Studies routinely show that while “pirates” are often maligned as freeloading ne'er do wells by the entertainment industry, they tend to be the biggest purchasers of legal content. One recent study out of the UK showed that 83 percent of copyright infringers first try to find the content they’re looking for from legal sources.

But instead of focusing primarily on providing better legal alternatives to piracy, the entertainment industry has long pushed for more draconian options, including demands that ISPs kick copyright infringers offline entirely for copyright infringement.

These kinds of scorched-earth tactics were a major reason for the massive backlash the industry faced during the SOPA/PIPA fight in 2011, experts note. “SOPA/PIPA was riddled with problems and it would be nonsensical to go down that road again,” Moss said. Meredith Rose, a lawyer for consumer group Public Knowledge, told Motherboard that the high costs of adhering to such laws also tends to disadvantage smaller competitors. “In the end, there's a very real risk that you end up increasing concentration of market power because the dominant player is the only one who can afford to bear the new costs of the law,” Rose warned, adding that “it's not always clear that the benefit from the law offsets the harms from increased concentration.”