Comments spread quickly online. One person sends out the information to other people and it spreads from there. That is the nature of social media. The outcome can be positive or negative. If you are looking to start social media at your business, you may be concerned about keeping a positive image to potential customers. This does take a lot of work, moderating comments and communicating with people who may have had trouble with your business.
In an article from Entrepreneur.com, they delve into some of the experiences of businesses trying to get their reputations back under control. One of the interest examples in the article describes the trials of a local business, Shady Maple Smorgasbord in East Earl, Pa. The Mennonite-run company had had a rumor spread that they were unwilling to serve customers of a military affiliation because of their religious belief of nonviolence. The article describes how the business went so far as to create a webpage to counter the rumor, which was completely untrue. While Shady Maple's situation may not be your situation and their response is not always the correct move, it still may give some solace when facing a negative social media situation.
You can read the entire article and find out how other companies have dealt with repairing their online reputation on Entrepreneur.com.