You can close down Napster and Scour (the latter is a song‑swapping site that actually seems to work better than Napster). What you can't close down is the knowledge to recreate them. There are already alternatives, such as Gnutella, which seems to have a far less centralised structure ...
my %MESSAGE_CONSTRUCTOR = ( SEARCH_RESPONSE, => 'MP3::Napster::Song->new_from_search', BROWSE_RESPONSE, => 'MP3::Napster::Song->new_from_browse', CHANNEL_ENTRY, => 'MP3::Napster::Channel->new_from_list', CHANNEL_USER_ENTRY, => 'MP3::Napster::User->new_from_user_entry',...