I would imagine any sort of product review classification system would be exploitable for abuse.
Anecdotal evidence: when my mother and her team were running for student council (in college), the opposing team introduced blatantly fake votes (photocopied) in favor of her team; my mother's team got disqualified for cheating, and the opposing team won.
So I could certainly picture a way in which a mischievous seller could submit fake-looking reviews for another product and get it taken down.
There’s nothing better than the support from the college administration of such behaviour by directly acting upon it. Some of these people now sit somewhere higher up.
Anecdotal evidence: when my mother and her team were running for student council (in college), the opposing team introduced blatantly fake votes (photocopied) in favor of her team; my mother's team got disqualified for cheating, and the opposing team won.
So I could certainly picture a way in which a mischievous seller could submit fake-looking reviews for another product and get it taken down.