Activision Blizzard video games buys King Digital for $5.9 bn

US video game producer Activision Blizzard has announced that it is buying King Digital Entertainment, best known for its "Candy Crush Saga" mobile game, for $5.9 billion. The "Call of Duty" series is one of the best selling console games in the world, while the addictive "Candy Crush" is among the most popular games on mobile devices.