After a photographer who’s allowed thousands of her images to enter the public domain filed a $1 billion lawsuit against Getty Images for allegedly threatening her for using her own photos, the photo agency says it will investigate the complaint, and “vigorously defend” if need be.

Last week, U.S. photographer Carol Highsmith filed a copyright complaint [PDF] against Getty Images, saying an agent with the company threatened her with legal action and demanded a $120 payment — for using her own photograph without its permission.

See, Highsmith has allowed tens of thousands of photographs of people and places in the U.S. to be used by the general public via the Library of Congress. But in her lawsuit, she claims that Getty and fellow photo agency Alamy offer 18,755 of her photographs plastered with their own “false watermarks” on their stock photo sites.

“The defendants [Getty Images] have apparently misappropriated Ms. Highsmith’s generous gift to the American people,” the complaint reads. “[They] are not only unlawfully charging licensing fees … but are falsely and fraudulently holding themselves out as the exclusive copyright owner.”

Though the cash demand for using her own photos was later dropped, Highsmith sued Getty last week for $1 billion. That figure was determined by calculating the maximum damages she can seek per each violation of copyright ($25,000), multiplied by 18,755 for each photo she claims was used. That comes out to $468,875,000, but, as Hyperallergic notes, because the company was found to have violated the same copyright law within the last three years, she can seek three times that amount.

“The economic damage that Ms. Highsmith has suffered includes, without limitation, any and all revenue received by the Defendants based on purported licenses sold for the Highsmith Photos. These funds represent money that Ms. Highsmith could have received had she attempted to monetize her photos through the Defendants,” the complaint states.

Getty now says it’s prepared to fight back if it has to.

“We are reviewing the complaint. We believe it is based on a number of misconceptions, which we hope to rectify with the plaintiff as soon as possible. If that is not possible, we will defend ourselves vigorously,” the company says in a statement reported by Torrent Freak.

Getty Images Bites Back in $1 Billion Copyright Dispute [TorrentFreak]

Photographer Files $1 Billion Suit Against Getty for Licensing Her Public Domain Images [Hyperallergic]