One of the new dimensions that all employers are going to face in an era of participatory media is more employee and contractor dialogue in the market. Some of it you are going to wish you heard first or could take off line. But that privilege is something the writer gets to extend - you don't get to demand it unless it breaches policies and the like.
Employers should view this as an opportunity. Take the feedback and revel in it. More than often it reflects a broader trend or opinion.