Hi Adena - First, DOI is much more than USGS - including FWS, NPS, and BLM among other heavy GIS users. Second, I am accessing this site from a DOI computer; the ban appears to block mostly URLs that are blog-specific, i.e. blogspot, typepad, etc. Blogs with "normal" URLs seem to get through. Lastly, there is a reason "only about 100 sites have been removed from the ban." It is because of typical gov't bureaucracy - here is the message we receive when trying to access a blocked site:

The World Wide Web is a dynamic and fast-changing place. If you believe the web page you are trying to reach is no longer classified correctly, you may notify the vendor responsible for classifying web sites for DOI by filling out the form located at: Submit A Site For Review. The vendor will review the information you provide and update system filters if appropriate. Please include the URL (e.g. http://website.com) you are attempting to reach.

If you believe this web site is categorized correctly and you have a legitimate business need to access it, please submit a request for exception to the Enterprise Security Officer, through your immediate supervisor to your Deputy CIO or higher authority.

So our choices are to submit the site to a vendor, which I did with arcpadteam.blogspot.com, to no effect. Or go up through the long chain of command to try to get a site unblocked, which is likely to have the same result.