Artist and software engineer David Huerta hopes that the NSA will never be able to listen to his mixtape. After the agency's surveillance programs and apparent attempts to weaken encryption came to light in 2013, he conceived of a musical homage to journalists Laura Poitras and Glenn Greenwald, who helped publish Edward Snowden's documents. As he didn't have a tape recorder, though, he decided to make a high-tech simulacrum by covering an Arduino electronics board with symbolically transparent acrylic. Storing the music on an encrypted SD card, he sent the device to the NSA's headquarters in Fort Meade, MD. The password stayed with him.

"Encryption is the blind spot to the NSA's all-seeing eye," Huerta wrote in a blog post in May. "Math doesn't need an information dominance center to enforce its rules. Math is the legal framework which the universe can only obey and will trump and outlast the rules of any human state." The NSA and other agencies have managed to get around encryption, but mostly by targeting weak links elsewhere in the system. A couple of days ago, Motherboard interviewed him, publishing more pictures of the encrypted tape. Notably not included in either post is information about Huerta's musical choices, and the only track list is kept carefully offline. "The NSA can read my stupid Facebook updates but without my consent it will never be able to listen to my kick-ass mixtape," he writes.