The Justice Department and state attorneys general allege that Google has paid Apple and smartphone makers including Samsung billions of dollars in revenue-sharing agreements to keep rival search engines from gaining users. The deals offer a percentage of the revenue Google makes from search-based advertising in exchange for being the default tool on browsers and smartphones. The Justice Department says Google pays more than $US10 billion a year in these contracts, although the exact figures remain confidential. Google denies that the agreements harm competition and says it’s easy for consumers to switch to alternatives if they want. Joan Braddi, Google’s...