Approximately a dozen Google employees have reportedly quit the company in protest over a new drone contract that Google signed with the Pentagon.

Google employees have reportedly argued for months over the company’s decision to help the U.S. Department of Defense analyze video footage gathered by military drones, the Silicon Valley Business Journal reports. Thousands of Google employees signed a petition stating that they oppose the company’s new project, now approximately a dozen employees have quit. The employees that chose to quit the company reportedly left memos to colleagues explaining their decisions, which ranged from ethical issues relating to Google helping the U.S. Military to issues with Google slowly losing public trust.

These memos have reportedly been gathered up into one large internal document which is being shared throughout the company. All of this is due to Google’s new development, Project Maven, which aims to use artificial intelligence to help military drones scan and identify what they see in the field, at the moment these tasks are mostly performed by human operators. Google has stated that the Pentagon receives the same access to the open-source TensorFlow APIs that any of their Google Cloud customers do and stressed that their technology was not being used to launch or fly drones.

An internal petition signed by approximately 4,000 Google employees reads: “While this eliminates a narrow set of direct applications, the technology is being built for the military, and once it’s delivered it could easily be used to assist in these tasks.” Google has also made the issue more serious by allegedly not being entirely forthcoming about their involvement in Project Maven. The company has not revealed if it will be providing engineering resources to the project or how much it will be paid.

Many groups have been critical of Google’s involvement in the project, such as the Electronic Frontier Foundation, which published an article recently urging Google to drop the project. Another petition from the Tech Workers Coalition reads: “We believe that tech companies should not be in the business of war, and that we as tech workers must adopt binding ethical standards for the use of AI that will let us build the world we believe in.”