NEW YORK – The video-sharing site YouTube will be allowed to mask the identities of individual users when it provides viewership records to Viacom Inc. and other copyright holders behind a $1 billion copyright-infringement lawsuit.

YouTube disclosed late Monday that it would substitute user IDs, Internet addresses and other identifiers before submitting the database to Viacom as required under a July 1 court order widely criticized by privacy activists.

“We remain committed to protecting your privacy and we'll continue to fight for your right to share and broadcast your work on YouTube,” the company said in a blog posting.

Viacom is seeking at least $1 billion in damages from YouTube's owner, Google Inc., saying YouTube has built a business by using the Internet to “willfully infringe” copyrights on Viacom shows, which include Comedy Central's “The Daily Show with Jon Stewart” and Nickelodeon's “SpongeBob SquarePants” cartoon.

U.S. District Judge Louis L. Stanton had dismissed privacy concerns as speculative in authorizing full access to the YouTube logs after Viacom and other plaintiffs argued that they need the data to show whether their copyright-protected videos are more heavily watched than amateur clips.

The YouTube database includes information on when each video gets played. Attached to each entry is each viewer's unique login ID and the Internet Protocol, or IP, address for that viewer's computer – identifiers that, while seemingly anonymous, can often be traced to specific individuals, or at least their employers or hometowns.

Lawyers for Viacom and the other plantiffs signed an agreement with YouTube on Monday saying they would accept measures to help YouTube preserve the anonymity of the records. Under the agreement, YouTube can swap the identifiers with other values under a protocol that YouTube has a week to propose.

The new values will still have to let the plaintiffs determine which individual watched which clip and when, but they will mask cases where an existing identifier contains personally identifiable information – such as first initial and full last name in a user ID.

In limited circumstances, it may still be possible to track records to a specific individual based on that person's viewing habits, as Time Warner Inc.'s AOL discovered when it released to academic researchers some 19 million search requests made over three months. AOL substituted numeric IDs for the subscribers' real user names, yet the items searched produced enough clues to track down some of the users and identify them by name.

In the YouTube case, the data would not be publicly released but disclosed only to the plaintiffs, likely under a court-sanctioned confidentiality order.

Still in dispute is whether YouTube would be able to anonymize records for its employees. If a YouTube employee had viewed an episode of “The Daily Show,” for instance, Viacom could argue that YouTube directly knew of copyright infringement.

Such a finding could dissolve the immunity protections that service providers generally have when they merely host content submitted by their users.

Viacom had no comment.