I forget who it is, but someone on FT has a signature that states, "The purpose of a system is what it does." In other words, it doesn't matter what you originally intended a system or device to do; the only thing that matters is what it actually DOES.

Interrogations by government actors, no matter their intent or results, are still interrogations, and are still covered by 1st, 4th, and 5th Amendment restrictions.