But ASCII null-terminated strings can't contain null either, so I don't know why he says that it's just a problem for UTF-8. Also, if you represent U+0000 by 0

But ASCII null-terminated strings can't contain null either, so I don't know why he says that it's just a problem for UTF-8. Also, if you represent U+0000 by 0xC0 0x80, then it's "Modified UTF-8", and it's not valid UTF-8.