well, doing this moderating malarkey does tend to sharpen ones appreciation of bogosity in all it's myriad manifestations! plus, there are tools at our disposal to trace any noxious posters, should the need arise.
and should we have suspicions about a particular review, albeit in the absence of any forensic evidence, then we simply won't post it. fortunately, we have no regard for freedom of speech whatsoever, which always helps in such matters...