Facebook co-founder Mark Zuckerberg's ambitious plan to provide Internet access to billions of people around the globe will face challenges that extend far beyond solving technical and financial issues...But nonprofit groups that have been focused on bridging the global digital divide have reported that such efforts inevitably run into problems including economics, culture, education and corruption...Still, Zuckerberg says he felt compelled to tackle an issue he says is crucial...Brian Wieser, a senior analyst at Pivotal Research, said Zuckerberg's announcement seemed more geared toward generating positive publicity for Facebook and honing its relationships with governments around the world...[Refers to Google, Microsoft]