Apple is suing a former employee for allegedly stealing confidential Vision Pro headset research before leaving to join Snap’s product design team. In the complaint filed in Santa Clara County Superior Court on June 24th, Apple accuses Di Liu of downloading thousands of documents containing proprietary information from Apple’s internal systems and saving them to his personal cloud storage account in his final days as a senior design engineer for the Vision Pro.

According to the lawsuit, Liu falsely claimed he was quitting his job for health reasons and did not disclose that he had a new job lined up as a product design engineer for Snap. This prevented Apple from immediately revoking Liu’s access to internal systems, a standard protocol activated by the company upon notice that employees are joining a competitor. Apple alleges that this allowed Liu to copy a “massive volume” of proprietary information that he could later access after being locked out of Apple’s network.

“Mr. Liu’s actions were deliberate; logs on his Apple-issued work laptop show that Mr. Liu individually selected the folders he copied and, in some cases, renamed and reorganized them after moving them to his personal cloud storage account,” Apple said in the complaint. “Further, Mr. Liu took actions to conceal movement of the files, intentionally deleting files from his Apple-issued work laptop.”

Apple says it’s unable to determine exactly what was downloaded by Liu, but argues the overlap between the information Liu took with Snap’s AR Spectacles products “suggests that Mr. Liu intends to use Apple’s Proprietary Information at Snap.” According to the complaint, Apple is pursuing unspecified financial damages from Liu for breaching contractual obligations and requesting that Liu be forced to return the stolen documents.

Apple has not named Snap as a defendant in the suit. Snap said in a statement to SiliconValley that it had reviewed Apple’s claims, and had “no reason to believe they are related to this individual’s employment or conduct at Snap.”