Apple has sent a cease and desist letter to a Chinese citizen who advertised selling stolen iPhone prototypes on social media. It is quite common for resellers in China to get their hands on stolen iPhone prototypes through Foxconn and Apple employees and then sell them for a premium to collectors.

It looks like Apple is coming down heavily on such resellers after first sending out legal warnings to many reliable leakers last month. The Vice reports that Apple’s law firm in China, Fangda Partners, sent a cease and desist letter in June to a reseller to stop selling and advertising stolen iPhone prototypes.

It also requested a list of people who provided the reseller with the leaked devices. Basically, the company wanted to know how the reseller could get their hands on the prototypes. Lastly, Apple wanted the seller to sign a document complying with the request within 14 days of receiving the letter.

“You have disclosed without authorization a large amount of information related to Apple’s unreleased and rumored products, which has constituted a deliberate infringement of Apple’s trade secrets,” the letter read.

“Through investigation, Apple has obtained relevant evidence about your unauthorized disclosure of Apple’s unreleased and rumored products,” the letter continued. “Your intentional infringement is specifically manifested as: publishing unpublished information about Apple’s new products through social media platforms, including but not limited to the design and performance of these new products.”

It is unclear what actions Apple intends to take against resellers who do not comply with their request. Whatever the case might be, it is clear that Apple is coming down heavily on leakers and resellers, so we might not get as many leaks as before for upcoming Apple products.