Four US firms rule the world's cloud infrastructure

There are plenty of companies vying for a piece of the worldwide cloud infrastructure market, but the top four -- all in the U.S. -- currently dominate by such a wide margin as to effectively leave their competitors in the dust.That's the overriding conclusion of a study released Monday by Synergy Research Group, which provides quarterly market tracking and segmentation data, including vendor revenues by segment and region.Amazon Web Services, Microsoft, IBM, and Google collectively control more