New Spider IP Address

This IP doesn't show up on any listings I've seen

[ThirdRock]

One of my sites just got hammered with more than 3,000 requests from this IP address:

72.3.225.**

It doesn't show up on any legitimate spider IP lists that I've seen before.

Any ideas?

[edited by: volatilegx at 2:11 pm (utc) on Mar. 7, 2006]
[edit reason] obscured IP address [/edit]

[volatilegx]

Welcome to WebmasterWorld ThirdRock :)

The IP is registered to Rackspace.com.

Sounds like a home-grown spider.