A group of US lawmakers on Wednesday proposed a bill that would make it illegal for employers or schools to require the disclosure of passwords for social networks such as Facebook. The bipartisan proposal comes after reports that some firms have required passwords as a condition of employment, or that schools have asked for the information to guarantee enrollment or participation in sports programs. The lawmakers said the bill, a reintroduction of a measure proposed last year, was aimed at protecting privacy in social networks like Facebook or Twitter.