More Stealth Crawling Hosted at OC3Networks

No clue who or what this crawler is but it's coming from OC3Networks datacenter.

Here's the IPs and the user agent coming from their network:

72.11.155.106 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.112 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.113 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.125 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.131 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.137 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.154 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.197 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.204 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.211 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.219 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.223 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.228 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.236 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.237 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.246 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.34 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.37 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.45 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.5 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.57 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.61 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.63 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.64 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.67 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)
72.11.155.90 Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; T312461; .NET CLR 1.1.4322)

Here's their ranges of IPs:

OC3 Networks & Web Solutions, LLC OC3-NETWORKS
66.63.160.0 - 66.63.191.255

OC3 Networks & Web Solutions, LLC OC3-NETWORKS
72.11.128.0 - 72.11.159.255

OC3 Networks ISWT-207-178-200-0
207.178.200.0 - 207.178.200.63

OC3 Networks OC3-NETWORKS-DSLUSERS
66.63.163.0 - 66.63.164.255

OC3 Networks OC3-NETWORKS--DEDICATED-SERVERS-RANGE
66.63.176.0 - 66.63.176.255

OC3 Networks OC3-NETWORKS--DEDICATED-SERVERS-RANGE
66.63.179.0 - 66.63.179.255

OC3 Networks OC3-NETWORKS---COLOCATIONS-VOIP
66.63.178.0 - 66.63.178.127

Not sure I'd block the DSLUSERS range but the rest look like fair game.

Enjoy.