In 2022, a class-action lawsuit was filed against Microsoft, GitHub, and OpenAI alleging that GitHub Copilot was trained on billions of lines of open-source code scraped from GitHub without honoring the original licenses. Copilot was found to reproduce GPL-licensed code verbatim without attribution — meaning it was effectively distributing copyrighted code for free. The lawsuit sought $9 billion in damages. It became the first major legal test of whether AI training on public code constitutes copyright infringement.