Amazon.com, Google, Facebook and a range of global digital platforms are facing a regulatory onslaught in the EU, as the European Commission floats a plan for a comprehensive overhaul designed to tackle digital \u201cgatekeepers,\u201d market concentration and online services. The biggest change is a new tool to investigate markets and impose behavioral or structural remedies \u2014 even when no company has been found to be in violation of competition laws. If adopted, the suite of proposals would mark a turning point in the EU\u2019s regulatory battle with Big Tech.