Dunno what to tell you, maybe if some fancy-shmancy analytics computations were used, maybe an answer could be defined.
I'll tell you this though... There are still signature patterns of spambots that the forum administration could help cut down.
All these spambots who register an account with a name ending in "zoro" or "toro" or "juriya" or "alex", it's gotten to the point that I don't report them any more because the forum staff is unable to ban/delete members if they don't post any spam first. If we had tools to cut down all spambots at all times, this could be countered somewhat. *Shrugs.