It simply means you cannot rely on DNS (and domain names and such) for your security; your security must be achieved via other means (user auth or such). DNSSEC

It simply means you cannot rely on DNS (and domain names and such) for your security; your security must be achieved via other means (user auth or such). DNSSEC does not help that much, in reality, despite the implication it might, and that's part of why SSL and Signed Certs exist - it's a given that when I connect to www.microsoft.com from starbucks wifi, the IP DNS returns may or may not be microsoft's. With DNSSEC - presumably you may have a higher level of assurance the IP is from Microsoft, but it is not really practical to implement everywhere due to complexity, so you cannot depend on it to solve for this sort of issue.