If you read the wrong books or the wrong articles, some will claim that IPv6 has improved security over IPv4. While this may be true in an extremely limited sense, for practical purposes there is no difference. The only way in which IPv6 is really more secure that IPv4 is that one cannot easily port scan a subnet. In some other ways, IPv4 might be more secure than certain implementations of IPv6, where the EUI-64 address is used as the lower 64 bits of the IP address, and thus enabling violation of privacy (e.g., tracking). The most absurd statement I just recently read was that NAT causes Spam. Where do these people get this stuff???