It appears that CBS is in trouble because of Dr. Sheldon Cooper (Jim Parsons) in “The Big Bang Theory”.

Contrary to fans’ belief, Sheldon did not harass anyone to warrant him a restraining order. Instead, the network is in trouble because of the song “Soft Kitty”.

BBC News reports that Ellen Newlin Chase and Margaret Chase Perry are suing CBS for copyright violations. The two, who are daughters of deceased nursery school teacher Edith Newlin in New Hampshire, claims that “Soft Kitty” is a poem their mother wrote and that the network used it without buying the rights.

According to the report, other media companies who also used the lyrics in their merchandise were sued by the sisters.

Sidney Morning Herald, meanwhile, provides a background of the song/poem’s copyright.

The website traces the history of the poem’s publication as detailed in the lawsuit filed by Chase and Perry. According to the details, “Song Kitty” first appeared in the book “Songs for the Nursery School” in 1937. The actual text was quoted as follows:

Soft Kitty, warm kitty
Little ball of fur
Happy kitty, sleepy kitty
Purr, purr, purr.

SMH details that the song/poem was copyrighted that very same year and copyrighted again in 1964.

Meanwhile, a report by USA Today also emphasizes that another thought at the center of the lawsuit is that audience were made to believe that someone from “The Big Bang Theory” actually wrote the song. The Sydney Morning Herald even recalls that at one point, Bill Prady (one of the people behind the show), was credited as the writer of “Soft Kitty”.

USA Today further details that Ellen Chase, who is now in her 70s, only learned of the song’s use in “The Big Bang Theory” when she was doing research for an article.

As of the moment, the progress of the lawsuit remains unknown and Warner Bros. did not release any comment about the issue.