The problem is, a continuous, consistent pattern of negative reviews can just as easily come from someone who has it out for a business. I have a friend who is

The problem is, a continuous, consistent pattern of negative reviews can just as easily come from someone who has it out for a business. I have a friend who is currently a target of such a vendetta. He got into an edit dispute with someone who was trying to censor stuff on a wiki. This other person responded by flooding listings of my friend's previous employer (which has been out of business for a few months) on nearly every review site out there with a continuous stream of utterly fabricated reviews. These reviews range from calling him a pedophile (easy enough to get deleted) to pretending to be a client who was screwed by his incompetence. I'm not sure there is any way to differentiate the latter kind of reviews from genuine negative experiences.