Who's still running the node, please shut down your node.
you cant make new user stop his sync if you not remove the wallet from website, and im sure controll all people to shutdown or turn off his wallet is very hard, this is decentralization system, no one cant stop it, better you find other way maybe with make new version of wallet and including new setup (block), and announce to all user to upgrader his version
lol imagine someone trying to get all the people running BTC to go offline at the same time..
if they cannot do shit because someone, who possibly never was here on the forums, has a node running then this coin is already dead and rotting.. jfc.. merely asking that and expecting blockchain network to shutdown itself is a blunt example of total lack of imagination