Should I be worried?
Nah, they're using Netscape 3.01 browser - probably couldn't even load the page.
This taken from SiteMeter stats:
sec.gov @ 3/23/2004 2:31:12 PM
Domain Name sec.gov ? (United States Government)
IP Address 12.40.163.# (AT&T Bell Laboratories)
Language Setting English
Operating System Unknown Unknown
Browser Netscape 3.01
Time of Visit Mar 23 2004 2:31:12 pm
Last Page View Mar 23 2004 2:31:12 pm
Visit Length 0 seconds
Page Views 1