Kill cord protects data on devices seized by government (Linux, Windows, macOS)
cnx-software.com
cnx-software.com
Of course most constitutions do forbid surveillance of private communications, we just used the last two decades to create enough exemptions that the fundamental rule in most constitutions is worthless by now. We needed protection from terrorism that causes nearly as much death as the sniffles (not counted the hundreds of thousands of dead by retribution to said terrorism!).
Enough information can make almost anyone a criminal or at least cause embarrassment enough to not let people be a force in society anymore. Even having the information is enough for people to stay silent, so tools like this may become essential for basically everyone, even if such a arms race against state actors does decrease overall security.