這是是韓國廠商 Hancom 在加州被告上法院：「A federal court has ruled that an open-source license is an enforceable contract」。
But after it began using Ghostscript in its software in 2013, Hancom did neither: it did not open-source its software, and it did not pay Artifex a licensing fee.
At the end of 2016, Artifex filed a lawsuit against Hancom in the US District Court for the Northern District of California.
Hancom 的理由是授權 (license) 不是合約 (contract)：
That happened when Hancom issued a motion to dismiss the case on the grounds that the company didn’t sign anything, so the license wasn’t a real contract.
而法官認定 GPL 是合約的一種：
“Not so,” said Judge Jacqueline Scott Corley in her order on the motion on April 25. Corley said the GNU GPL “provides that the Ghostscript user agrees to its terms if the user does not obtain a commercial license. Plaintiff alleges that Defendant used Ghostscript, did not obtain a commercial license, and represented publicly that its use of Ghostscript was licensed under the [GNU GPL]. These allegations sufficiently plead the existence of a contract.”