Dragnet demanding your password at the border is something we know they do - there are loads of witnesses saying they were asked for passwords at borders. Dragnet hardware tampering of electronics in the mail is not something we know they do.
I've only seen two articles claiming evidence of physical tampering - like a hoax about Dell from 2005 [1] and Bloomberg's dodgy story about spy chips from last year [2] - neither of which seems truthy, and neither of which involved mail interdiction.
(Of course, it's widely suspected mailed hardware can be tampered with, but most of the claims/speculation I've read has been about targeted tampering, not dragnet)
I've only seen two articles claiming evidence of physical tampering - like a hoax about Dell from 2005 [1] and Bloomberg's dodgy story about spy chips from last year [2] - neither of which seems truthy, and neither of which involved mail interdiction.
(Of course, it's widely suspected mailed hardware can be tampered with, but most of the claims/speculation I've read has been about targeted tampering, not dragnet)
[1] https://www.snopes.com/fact-check/keyboard-loggers/ [2] https://techcrunch.com/2018/10/04/bloomberg-spy-chip-murky-w...