zlacker

But then a single user clicking on links quickly would bring your webserver to its knees. So much for using those addresses to combat abuse... :)

Plus the FBI could probably narrow their search to a few hundred thousand addresses (relevant ISPs, no unroutable/multicast/etc), then only use the list to confirm.

Finally, if it takes 120 years on one core, it'll take 1.4 months on 1000 cores. I'm willing to be the FBI has access to more computing power than I do. ~100 CPU years isn't a particularly daunting amount of computing work, even for fairly low stakes research.

That search would also decode all addresses in the logs, not just one targeted one...