I tried to report a thread to the moderator and received this error ???
may be because it was deleted 
;D
Not maybe, it was definitely deleted, if you are talking about the drive by spamming of three posts by the same person, they were all deleted.
I too reported or attempted to report them but action had already been taken.
My question is "Why are we getting so many of these spammers ???
I thought that precautions had been instituted to stop this sort of thing ???
The precautions are if we are talking about the image capture of alpha numeric characters, then that is a) designed to stop automated registering to spam or abuse sites b) I read an interesting article that this too is being circumvented and will soon need to adapt/change.
This however, doesn’t stop manual registering on the forums and posting spam, then it is the intervention of users reporting it quickly and have the posts deleted (and forum membership if necessary) to make it worthless in doing it.