She also elaborates on the FBI's policy around revealing Stingray use. The bureau doesn't ask police to deny using Stingrays in the first place, Hess claims... it just doesn't want them explaining the exact functionality in public. Investigators can detail things to judges in private sessions if there are any questions, although this isn't going to be very reassuring if you're caught by one of these surveillance sites.

Hess is quick to admit that the zero-day attacks are problematic: the FBI has to strike a balance between catching possible criminals and responsible disclosures that protect the public. However, there are concerns about whether or not it's making the best choices. After all, this is the same outfit pushing for backdoor access that, in practice, would likely leave everyone vulnerable. While the FBI may be thinking carefully before compromising someone's device, it may not end up making the right call.

[Image credit: Michael S. Williamson/The Washington Post via Getty Images]