Okay - here's where my mind went when presented with this problem: be like an ombudsman. When I call up the TIO (http://www.tio.com.au/ http://www.tio.com.au/)

Okay - here's where my mind went when presented with this problem: be like an ombudsman. When I call up the TIO (http://www.tio.com.au/ http://www.tio.com.au/) to complain about my mobile phone supplier, the first thing they do is give me a reference number and a phone number at the company that is reserved for "high level" customer service enquiries (ie. I get to speak to a "case manager" rather than having to navigate the layers of support from the ground-up). So give the company that the review is about a chance to respond prior to publishing the bad review. If they don't respond, publish it. If they do respond, then you can still publish the bad review but the OP may edit it so that it's not quite so caustic. This could be regulated quite easily by requiring the OP to provide a valid contact email address and URL for the company about which they're providing a review. Or you could do like the TIO does and provide the customer with a reference number to contact the company they originally dealt with and allow the company to login and use that same reference number to tell their side of the story. Your company is then like, OmniOmbudsman :) (.com ... take it, it's available)