Here's what the perpetrators say (as I now see I should have guessed
from their domain name).

It's for the Web Server Survey

    http://www.netcraft.com/survey/

Every month, we publish the Netcraft Web Server Survey which is a survey of
the number of web sites that we can find on the Internet, and the software
used by these sites.

The survey is read avidly by the server development companies such as
Netscape, Microsoft, O'Reilly etc, and is regularly reported by the
computer press.

We use several techniques in order to find new sites, and one of them is 
to walk the DNS. Zone transfers have been part of the survey research 
since November 1995 and although a few sites ask for clarification each month,
they seem happy once they know the intended purpose.

I hope that's okay.

Mike
-- 
Mike Prettejohn                          http://www.netcraft.com
[log in to unmask]    Phone +44 1225 447500    Fax +44 1225 448600
Netcraft  Rockfield House Granville Road  Bath  BA1 9BQ  England