system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How has no country been aware of the US hacking their systems?

I really just don't get this. How can these massive technological companies and international powers not have had any inclination that their telephones and computers were being hacked?
gpt
Tapping is very different from hacking. Hacking is much more detectable, because it generally involves compromising a device you are using.

The kind of tapping under discussion here is just making a copy of the data as it travels over the line, not at the destination. The equivalent metaphor would be the post office taking pictures of postcards as they go through the system. Would you know when the postcard arrives if the post office made a copy of it?