A bipartisan group of attorneys from 20 states in the United States are preparing to begin an antitrust investigation of the tech giants. They are expected to formally launch a probe to assess whether tech companies are using their dominant market position to hurt competition. The initiative echoes pre-existing efforts to investigate the impact of tech giants on competition. The Justice Department announced its antitrust review focused on tech companies, and the Federal Trade Commission is investigating antitrust concerns at Facebook, including the company's acquisition of nascent tech companies, as well as other competitive issues elsewhere in the tech industry. Authorities worry that significant parts of the tech sector have become uncompetitive, including advertising, search, social media, app sales and certain retail sectors, among others.