Rick,
Similar to what I expressed already in email directly to you, data
without timestamp of when a specific IP address was found to be an
offender is nearly worthless for action, and only interesting as
statistical chatter.. Except where you perhaps have business customers
(and the occasional residential customer) with static address
assignments. Even still, acting on such 3rd party derived data for
things like AUP enforcement is probably still more problematic...
I understand the difficulty of coming up with a valid timestamp, but the
other part of this is operational realities that IP addresses temporary
assignments for a lot of broadband subs.
So, I guess, I wonder -- with the deficiencies indicated above -- what
operational use such a list would really have in the end. 
Other
than yet another interesting metric of just how bad things are out
there(TM).
Regards,
Christian