> "if you can send and receive a bit, you can send and receive anything."

No, needs work.

Part 1 - No system can be 100%, then you hit the Two Generals' Problem..

Part 2 - Just because you can send a bit, that doesn't mean you can send 8 in a row. So you write a protocol, then they block that protocol, you adapt, they adapt etc etc

Maybe something like ~ any system where you have any control over information flow someone has written a protocol to send porn over it.

That's just jumping of Rule 34, you could change porn to something else