What "forum"? Perhaps a bit of reading up on the way Usenet (yes, you
are posting to Usenet, not to Google(TM) Forums(TM)) works is in order.
The term "forum" is generic term for a place for discussion; this
newsgroup certainly qualifies. The term "newsgroup" is more precise,
but not particularly more accurate. (And it's called Google Groups,
not Google Forums.)
The answer to the original question is basically no. This is an
unmoderated newsgroup. There is no central authority. Multiple
servers all over the world share articles, and automatically forward
them to each other. Some individual servers may do some spam
filtering (so many readers may not have seen the original spam), but
there's no central filtering -- and no central anything else.
If you see spam in this newsgroup, it's best to simply ignore it. You
can report the spammer to his/her ISP if you like, but most likely
someone else has already done so -- and headers are often forged, so
it can be difficult to tell who the ISP is. Posting a followup to a
spam is not useful; the spammer will never see your followup, and it
merely reduces the signal/noise ratio.
