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.
“I would say that Bob Dylan is as interested in money as any person I've known in my life. That's just the truth.”
“I come from a modest background. I put myself through college and law school and a postdoctorate program in tax law.”