I http ward an interesting rumour regarding Symantec.cloud (formerly MessageLabs) at InfoSec Europe about the implications of IPv6 rollout.

One of the methods currently used for combating spam is through blacklisting of IP addresses. In the new IPv6 world, Symantec will be whitelisting the IPs of mail servers. It’s understandable why but I suspect it will generate a lot of debate when people realise the implications.