Job seekers have nightmare stories about people who learned a hard lesson in the age of social media. Companies visit social sites to check out potential candidates, and if you’re the one asking to be hired, you don’t want your named tagged in Facebook photo of you dancing drunkenly on a bar in a bikini (especially if you’re a guy).Employee manuals commonly include strict rules about what can and can’t be said online, even from private accounts — with a threat of terminating the employee for violating policy. No can do, says the National Labor Relations Board. The NLRB, first formed to protect unions, says workers have the same right to discuss work on Facebook, Twitter, and other social networks as they do at the water cooler. Barring a breach of confidentiality, employers cannot fire you for talking trash online.