said by ground:said by TomS_:What stops them doing whatever they want now?
What do you mean what stops them? My router does - I have half of Internet blocked here. They can't even get online without being properly authenticated on the router.
Now with IPv6 they will come with their laptops, get public IPs, download Gigs of pron/send spam/DDoS other sites. How you're going to control them without a router? NAT allows you to put them in a sandbox and set your own rules.
Having a public IP does not mean you are exempt from firewalls, ACLs, access restrictions etc.