New York, January 22 - Badmouthing the boss on Facebook or Twitter in the US until recently could get employees into lots of trouble and even lead to firing. But no longer. Through a series of recent rulings, the National Labor Relations Board (NLRB), a federal regulatory agency which has jurisdiction over workplace issues at nearly all private sector employers, has declared that workers have the right to express themselves freely about their jobs, work conditions, bosses and other company issues on social networks without having to worry about the consequences to their salaries, promotion prospects or jobs. Blanket restrictions on the use of social media at work are illegal, the NLRB has determined. According to the New York Times, the board's rulings have gone so far as to call for the reinstatement of various workers fired for their posts on social networks. In addition, the Times reports, the NLRB has asked companies including General Motors, Target and Costco, to rewrite their social media rules. The board's rulings, says the Times, "generally tell companies that it is illegal to adopt broad social media policies - like bans on disrespectful comments or posts that criticize the employer - if those policies discourage workers from exercising their right to communicate with one another with the aim of improving wages, benefits or working conditions". However, the rulings don't protect lone employers who rant against their company on the Internet.