It looks like this may indeed be the real Tom Metzger, American founder of the White Aryan Resistance and failed candidate for US Congress and Senate. (The IP address is in Indiana, where he lives.)
tom metzger »No body likes a cry baby or a snitch. It makes you look like a jerk.
08.18.09 - 6:38 am
I banned him, as I have no interest in having neo-Nazis or white supremacists running around my site, even if the messages are just sillier than they are racist.
I'll just have to risk looking like a jerk to a group of bigots.
(Google is still displaying the ad. Do a search for "Zionism" and refresh the page a few times, the ad will show up at some point on the right.)
UPDATE: Google did respond to my complaint and says it is investigating.