Major internet providers are ending a four-year-old system in which consumers received “copyright alerts” when they viewed peer-to-peer pirated content.

The ISPs, studios, and record labels did not extend a pact that implemented the voluntary program, viewed as a way to fight piracy without the need for congressional legislation. When it debuted in 2013, it was viewed as a major new initiative to fight piracy, with Internet users subject to repeated notices if they continued to access infringing content. Those who ignored six or more multiple warnings faced possible penalties, including the slowing down of their Internet delivery, although the set of possible measures did not include having their Internet service cut off.

Although no reason was given for ending the program, the MPAA, in a statement from its general counsel, indicated frustration at the inability to stop repeat infringers.

“These repeat infringers are the ones who drive ongoing and problematic P2P piracy,” Steven Fabrizio, executive vice president and global general counsel at the MPAA, said in a statement. “In fact, an estimated 981 million movies and TV shows were downloaded in the U.S. last year using P2P. “

He said that the copyright alert system “was simply not set up to deal with the hard-core repeat infringer problem. Ultimately, these persistent infringers must be addressed by ISPs under their ‘repeat infringer’ policies as provided in the Digital Millennium Copyright Act.”

Years in the making, the copyright alerts were the result of a voluntary agreement between Internet providers — including Altice, Comcast and AT&T, Charter Communications and Verizon — and the MPAA and the Recording Industry Assn. of America. It was seen as a way to fight piracy via voluntary agreements rather than congressional legislation.

But forging an agreement took years, as ISPs had significant concerns over liability issues, as they would be in the position of penalizing some of their customers who failed to stop viewing pirated material.

So as part of the ultimate agreement, the industry groups set up the Center for Copyright Information to administer the program, also set up a way for those who received notices to challenge them in a review by the American Arbitration Association.

On Friday, the Center for Copyright Information issued a joint statement saying that “after four years of extensive consumer education and engagement, the Copyright Alert System will conclude its work.”

“The program demonstrated that real progress is possible when content creators, Internet innovators, and consumer advocates come together in a collaborative and consensus-driven process,” the statement said. “CAS succeeded in educating many people about the availability of legal content, as well as about issues associated with online infringement. We want to thank everyone who put in the hard work to develop this program and make it a success, including past and present members of our Advisory Board. While this particular program is ending, the parties remain committed to voluntary and cooperative efforts to address these issues.”

The system was based on the notion that many consumers are unaware that they are accessing infringing material, and would stop once they are informed.

Fabrizio said that the copyright alert system did demonstrate that a “significant number” of users stopped accessing the pirated content, but said that “a persistent group of hard-core, repeat infringers are unlikely to change their behavior.”

Another challenge was that the system applied only to P2P piracy, while the nature of copyright infringement has morphed into other areas like online streaming.