Snapchat is on Monday looking to clarify exactly how and when law enforcement agencies can access your “self-destructing” messages. According to a new blog post from Micah Schaffer, who handles matters pertaining to trust and safety at the company, Snapchat can only retrieve snaps that are unopened. Once a message has been viewed by its intended recipient, Schaffer says it’s permanently deleted from Snapchat’s Google-hosted cloud service. But unopened snaps are different; they can be manually fetched by the company in response to certain law enforcement requests — and only such requests. “Do we manually retrieve and look at snaps under ordinary circumstances? No,” Schaffer writes. “If we receive a search warrant from law enforcement for the contents of snaps and those snaps are still on our servers, a federal law called the Electronic Communications Privacy Act (ECPA) obliges us to produce the snaps to the requesting law enforcement agency.”