Sounds like you've been reading the usual trash from the Daily Express or Breitbart or whatever. If the price of a product included all externalities, then yes

Sounds like you've been reading the usual trash from the Daily Express or Breitbart or whatever. If the price of a product included all externalities, then yes regulation isn't needed, however it doesn't and can't, and this is where the usual anarcho-libertarian views fall down.