This is pretty clearly hacker traffic as the same IP is basically trying out different user agents one after another...the same thing is coming in from different networks:
1 74.86.171.82 5/2/2008 11:54:44 AM Mozilla/4.0 (compatible; MSIE 5.0; Windows 98)
2 74.86.171.82 5/2/2008 11:54:44 AM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; InfoPath.1)
1 74.86.171.82 5/2/2008 11:54:43 AM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; MyIE2; MRA 4.4 (build 01348))
2 74.86.171.82 5/2/2008 11:54:43 AM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)
2 74.86.171.82 5/2/2008 11:54:43 AM Mozilla/5.0 (Windows NT 5.1; U) Opera 7.54 [ru]
3 74.86.171.82 5/2/2008 11:54:43 AM Mozilla/5.0 (compatible; Googlebot/2.1;+http://www.google.com/bot.html)
4 74.86.171.82 5/2/2008 11:54:43 AM Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)
2 74.86.171.82 5/2/2008 11:54:42 AM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; http://www.tropicdesigns.net)
1 74.86.171.82 5/2/2008 11:54:42 AM Mozilla/4.0 (compatible; MSIE 5.0; Windows 98; DigExt; MRA 4.0 (build 00768))
3 74.86.171.82 5/2/2008 11:54:42 AM Mozilla/4.0 (compatible; MSIE 5.0; Windows 98; DigExt)
1 74.86.171.82 5/2/2008 11:54:42 AM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; MRA 4.1 (build 00975))
4 74.86.171.82 5/2/2008 11:54:42 AM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)
2 74.86.171.82 5/2/2008 11:54:42 AM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)
6 77.188.143.240 3/21/2008 12:02:48 AM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)
5 77.188.143.240 3/21/2008 12:02:47 AM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)
6 77.188.143.240 3/21/2008 12:02:47 AM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322)
6 77.188.143.240 3/21/2008 12:02:45 AM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET)
12 77.188.143.240 3/21/2008 12:02:45 AM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; InfoPath.1)
8 77.188.143.240 3/21/2008 12:02:44 AM Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.7) Gecko/20060909 Firefox/1.5.0.7
3 68.178.99.210 3/20/2008 5:46:16 PM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)
1 84.121.217.19 3/20/2008 3:13:25 PM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET)
2 84.121.217.19 3/20/2008 3:13:24 PM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; InfoPath.1)
2 84.121.217.19 3/20/2008 3:13:23 PM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)
2 84.121.217.19 3/20/2008 3:13:23 PM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322)
1 84.121.217.19 3/20/2008 3:13:22 PM Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)
1 84.121.217.19 3/20/2008 3:13:21 PM Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.7) Gecko/20060909 Firefox/1.5.0.7