Jeff Chan wrote:
I should add, this kind of data is only useful in proving a blackhat registrar if we also know how many other domains they have registered.
...
On the other hand some general information about the number of domains some large registrar holds is available at registration statistics sites like:
http://www.whois.sc/internet-statistics/registrar-stats-2003.html
According to that stat Schlund.de (1and1.com) is #8 worldwide with over a million live domains and almost a quarter of a million registered last year.
Joe