Even if it was a difficult operation to copy a song, it only takes one person to do it. After that the spread of the song via the Internet or other means of propagation is only limited by the honesty of the users.
“One could make money and get a career going with a low-budget horror film about killers attacking on holidays. It is always flattering to have somebody copy you.”
“If I needed to record, I'd head to the coast or Nashville, one or the other.”