Computers leak secrets. Not just through invasive ad tracking, data-stealing malware, and your ill-advised oversharing on social media, but through physics. The movements of a hard drive’s components, keystrokes on a keyboard, even the electric charge in a semiconductor’s wires produce radio waves, sound, and vibrations that transmit in all directions and can—when picked up by someone with sufficiently sensitive equipment and enough spycraft to decipher those signals—reveal your private data and activities. This category of spying techniques, originally codenamed TEMPEST by the National Security Agency but now encompassed in the more general term “side-channel attacks,” has been a known problem in computer security for close to eight decades, and it’s one that the United States government carefully considers in securing its own classified information. Now a pair of US lawmakers are launching an investigation into how vulnerable the rest of us are to TEMPEST-style surveillance—and whether the US government needs to push device manufacturers to do more to protect Americans. On Wednesday, Senator Ron Wyden and Representative Shontel Brown released a letter they sent …