Anyone can write unsolicited reviews for anyone, with an option of it being visible only to the manager (aka graffiti in the executive washroom).
If someone gets pissed off about his transhumanism (especially if he starts talking about the Singularity on eng-misc, or if he has questions related to assigning Real Names to AIs, or if someone just doesn't like Canada and won't forgive him for his work with Our Lady Peace in 2000-1) and decides to "Perf" him, he could be in trouble.
If someone like Ray Kurzweil ends up on a PIP I will call the fabric of the universe broken.