I think there is a mistyping.
I think the correct one would be as follows.
"Be aware that when copy and pasting private keys that you should use a usb live linux distribution which was never connected to the internet."
How to sign a Bitcoin message using your private key
I think there is a mistyping.
I think the correct one would be as follows.
"Be aware that when copy and pasting private keys that you should use a usb live linux distribution which was never connected to the internet."