The European Union has finally approved Facebook’s $19 billion acquisition of WhatsApp, almost six months after the deal was given the green light by US regulators. It’s the social network’s biggest purchase to date, and it gives it a major presence in the mobile messaging industry. The deal also gives WhatsApp the power to mount its biggest fight yet against the networks and traditional text messaging, but EU Commissioner Joaquin Almunia believes that the success of rival messaging services like Viber and Line won’t lead to total WhatsApp domination.