The owner of the music of "A Charlie Brown Christmas" and other "Peanuts" television specials filed four lawsuits Wednesday against defendants including the U.S. Department of the Interior, alleging they illegally used the jazzy ditties of pianist Vince Guaraldi in social media posts and a video game.

Lee Mendelson Film Productions filed the suits in federal courts in New York and Washington, D.C. The defendants also include a video game company, an auction house and a belt-maker.

One lawsuit argues the Interior Department did not have permission to use Guaraldi's arrangement of "O Tannenbaum" from "A Charlie Brown Christmas" in a digital holiday card posted to social media.

The department said in an email to The Associated Press that it does not comment on litigation.

Another lawsuit alleges Heritage Auctions illegally used "Linus and Lucy" - the beloved non-Christmas song the kids dance to in "A Charlie Brown Christmas" that has become the de facto "Peanuts" theme - in posts on Facebook and Instagram promoting an auction of collectibles. Similar claims of social media misuse come in another suit against Buckle-Down Inc., a belt company that makes "Peanuts" themed products.

Christina Rees, a representative of Heritage Auctions, said in an email, "At this time, Heritage has not been served with or reviewed the complaint. If and when we receive it, we will review the allegations and respond as appropriate."

Email messages seeking comments from the other defendants were not immediately answered.

The company decided to take the sweeping action after what they said was becoming an intolerable digital glut of unfair use of the music.

Attorney Marc Jacobson said in a statement that Lee Mendelson Film Productions "will no longer tolerate companies using their property without a license, especially in this era of instant digital sharing." He said "the rights of creators and the protection of iconic cultural assets must be vigorously enforced."

Peanuts Worldwide LLC, which owns the rights to Charlie Brown, Snoopy and the other characters, is not a party in any of the lawsuits.

The fourth suit alleges video game publisher GameMill Entertainment, in its 2025 "Peanuts" video game Snoopy & The Great Mystery Club, violated copyright by using new music compositions meant to invoke Guaraldi's pieces including "Linus and Lucy" and "Skating." The plaintiffs said no permission was sought for the music, and the copycat versions are too close to the originals not to require it.

Lee Mendelson Film Productions is seeking varying financial damages from the different defendants, including at least $300,000 from GameMill. And in every case, the plaintiff is seeking a judge's injunction that the alleged copyright violations immediately stop and not be repeated.

The story behind "A Charlie Brown Christmas"

Lee Mendelson Film Productions of Burlingame, California, was founded by and is named for the producer who collaborated with "Peanuts" creator Charles Schulz and director Bill Melendez to create the TV specials based on Schulz's comic strip, starting with 1965's "A Charlie Brown Christmas." Mendelson, who died in 2019, hired the jazz pianist Guaraldi to provide the mellow, often melancholy music, including "Christmas Time Is Here" and "Linus and Lucy."

Jason Mendelson, Lee Mendelson's son, told CBS News in 2021: "My father called Charles Schulz and he said, 'Hey, I just sold 'Charlie Brown Christmas' to CBS.' And Charles Schulz said, 'What's that?' And my father said, 'It's something you and I have to write over the weekend!'"

Schulz agreed to write the script, but the special would need just the right music – and that's when Mendelson heard a Guaraldi song on the radio.

Guaraldi was a rising San Francisco jazz pianist; his "Cast Your Fate to the Wind" had won a Grammy. Mendelson thought that it had the perfect sound for Charlie Brown.

He was right. Guaraldi's music became forever associated with Peanuts. But the opening song of the TV special became forever associated with Christmas.

The song was just piano, bass and drums, but Mendelson thought that it should be sung. With time running out, he wrote the words himself.

"Lee just dashed off some lyrics, like, basically on the back of a paper bag or something," said Cary Cedarblade.

The children's singing voices belonged to Cedarblade, Dan Bernhard, Dave Willat, and a few other members of the St. Paul's Episcopal Church youth choir, in San Rafael, California. "It's fun to work with the kids," Guaraldi once said. "And this group here is fabulous."