The IPv6 protocol rolled out earlier this month to prevent the world running out of IP addresses, but with an increase in complexity comes a difficulty in management — and possibly crime prevention. Law enforcement agencies including the FBI and DEA are reportedly worried about the potential loss of tracking abilities that will come with the shift to the new system. It's not that IPv6 is inherently any less secure, but that new addresses will be handed out by the American Registry for Internet Numbers (ARIN) on a much less regular basis. As such, the fear is that internet service providers will have less incentive to keep their sections of the public IP databases updated. As an FBI spokesman told CNET:

An issue may also arise around the amount of registration information that is maintained by providers and the amount of historical logging that exists. Today there are complete registries of what IPv4 addresses are "owned" by an operator. Depending on how the IPv6 system is rolled out, that registry may or may not be sufficient for law enforcement to identify what device is accessing the Internet.

Looking up public IP addresses can help ascertain the sources of spam mail and DDoS attacks as well as the identity of individuals, though the accuracy has been called into question. John Curran, president of ARIN, says that internet service providers are willing to assist in this, but the large blocks of IPv6 addresses handed out to them every 10-15 years mean that they could get "lazy" when it comes to updating their public registry — and ARIN won't be able to use its IP-allocating role as leverage.

If police are unable to use IP public registries, they may have to resort to subpoenas or court orders to find out information from a service provider, which could be a significantly time-consuming process. The FBI and Royal Canadian Mounted Police both agree that if the industry can't self-regulate a solution, it may be necessary to push for legislation — and this wouldn't be the first time we've heard of the FBI wanting to alter the law to keep up with advances in technology.