After banning the domain amazonaws.com because they are hosting bots.
I get all of this.

Agent: webclient
75.101.206.181 ec2-75-101-206-181.compute-1.amazonaws.com
Agent: webclient
75.101.206.181 ec2-75-101-206-181.compute-1.amazonaws.com
Agent: mozilla/4.0 (compatible; msie 7.0; windows nt 5.1; .net clr 1.1.4322)
67.202.31.132 ec2-67-202-31-132.compute-1.amazonaws.com
Agent: mozilla/4.0 (compatible; msie 7.0; windows nt 5.1; .net clr 1.1.4322; .net clr 2.0.50727)
67.202.31.132 ec2-67-202-31-132.compute-1.amazonaws.com
Agent: mozilla/4.0 (compatible; msie 7.0; windows nt 5.1; .net clr 1.1.4322)
67.202.57.15 ec2-67-202-57-15.compute-1.amazonaws.com
Agent: mozilla/4.0 (compatible; msie 7.0; windows nt 5.1; .net clr 1.1.4322; .net clr 2.0.50727)
67.202.57.15 ec2-67-202-57-15.compute-1.amazonaws.com

Agent: mozilla/4.0 (compatible; msie 7.0; windows nt 5.1; .net clr 1.1.4322; .net clr 2.0.50727)
67.202.57.15 ec2-67-202-57-15.compute-1.amazonaws.com

Agent: Mozilla/5.0 (compatible; zermelo; +http://www.powerset.com) [email:paul@page-store.com-crawl@powerset.com]
72.44.49.121 ec2-72-44-49-121.z-1.compute-1.amazonaws.com

Agent: AideRSS/1.0 (aiderss.com); * subscribers
67.202.34.44 ec2-67-202-34-44.compute-1.amazonaws.com


-----Update AideRSS just does not get it that they have been blocked.
67.202.23.122 ec2-67-202-23-122.compute-1.amazonaws.com
[06-17-2008-16:07:52] Scan Blacklist Domain Ban: amazonaws.com
Agent: AideRSS/1.0 (aiderss.com); * subscribers
75.101.226.160 ec2-75-101-226-160.compute-1.amazonaws.com
[06-17-2008-16:09:04] Scan Blacklist Domain Ban: amazonaws.com
Agent: AideRSS/1.0 (aiderss.com); * subscribers
75.101.219.174 ec2-75-101-219-174.compute-1.amazonaws.com
[06-17-2008-16:09:19] Scan Blacklist Domain Ban: amazonaws.com
Agent: AideRSS/1.0 (aiderss.com); * subscribers
67.202.21.42 ec2-67-202-21-42.compute-1.amazonaws.com
[06-17-2008-16:09:22] Scan Blacklist Domain Ban: amazonaws.com
Agent: AideRSS/1.0 (aiderss.com); * subscribers
67.202.23.83 ec2-67-202-23-83.compute-1.amazonaws.com
[06-17-2008-16:09:29] Scan Blacklist Domain Ban: amazonaws.com
Agent: AideRSS/1.0 (aiderss.com); * subscribers
75.101.211.7 ec2-75-101-211-7.compute-1.amazonaws.com
[06-17-2008-16:09:35] Scan Blacklist Domain Ban: amazonaws.com
Agent: AideRSS/1.0 (aiderss.com); * subscribers
75.101.244.65 ec2-75-101-244-65.compute-1.amazonaws.com
Agent: AideRSS/1.0 (aiderss.com); * subscribers
67.202.61.94 ec2-67-202-61-94.compute-1.amazonaws.com


Update

67.202.31.132 is BLACKLISTED by dnsbl.njabl.org for spam
67.202.61.94 is BLACKLISTED by dnsbl.njabl.org for spam
67.202.23.83 is BLACKLISTED by dnsbl.njabl.org for spam
67.202.21.42 is BLACKLISTED by dnsbl.njabl.org for spam
67.202.23.122 is BLACKLISTED by dnsbl.njabl.org for spam
67.202.34.44 is BLACKLISTED by dnsbl.njabl.org for spam
67.202.57.15 is BLACKLISTED by dnsbl.njabl.org for spam


The following comment is associated with this record: This network is a member of a dynamic hosting environment. See http://ec2.amazonaws.com/
It was added to the list: Tue Apr 1 12:41:39 2008 EST

spam source means the system was found via manual spam header parsing to be the origin of spam.

update july 15th
Agent: firefox/2.0.0.6 (ubuntu-feisty)
72.44.48.95 ec2-72-44-48-95.compute-1.amazonaws.com