[nimbius]

i wonder if we're not conflating xray with terahertz radiation perhaps? the former being used by a company called corrections one that produces a horrifying whole-body X-Ray of a prisoner to detect contraband (certainly not healthy.)

Terahertz radiation is used in airports with (arguable) safety and efficacy. the resolution is sufficient to read protest statements written under a passengers shirt in metallic ink. I wonder if it could read cards should they be specially crafted similarly.