Social media is a powerful tool for companies and brands, writes Lisa Barone, but if your social-media team makes dumb mistakes, it can quickly become a liability. Companies that use their social-media platforms to whine, complain, spam their customers or abuse other social-media users are cruising for a bruising, Barone argues. "Do any of these social-media behaviors sound familiar? If so, smack yourself. Then stop doing them," she writes.