I think that the best you'll get from anyone is a guess. My guess is that there was a lot of interlinking between all of the owners sites, and some of them were pretty risky sites - www. xxx-directory .org, etc.
I couldn't even find them in Google a few weeks ago when I was searching for the biz directory. All I found was a bunch of sites talking about it.
hundreds of free directories use that script. Those diretories have side-wide links to a bad neighborhood. thta's my real concern.
in past time, many directories are blacklisted by google due to their paid listings and spam stuff, Google is taking re-inclusion if the site will be reworked with good contents
My personal believes are that over thousands and thousands of websites uses the biz-directory script, the free versions all have side-wide links to the biz-directory.org website. Quite a few number of websites (directories) are considered to be a bad-neighberhood because of the content of those websites and these websites link to the biz-directory.org domain. Not very good imo. First the pr dropped and now they are completely gone from the index. See for instance all of these websites have links to the biz: http://search.yahoo.com/search?p=li...tory.org/+gambling&ei=UTF-8&fr=sfp&fl=0&x=wrt or http://search.yahoo.com/search?p=link:http://www.biz-directory.org/+xxx&ei=UTF-8&fr=sfp&fl=0&x=wrt