It is a long trek from Santa Clara, Redmond and Palo Alto to the corridors of the European Commission in Brussels. Flights from San Francisco to the Belgian capital take at least 13 hours, and trips from the other centres of the US technology and software industry clustered on the Pacific Rim are even more laborious.

Yet every week, planes arriving at Brussels Zaventem airport spill out a small, red-eyed army of lawyers, software engineers and executives from the US west coast. They all come to see the European Union's top antitrust regulator and they all have the same goal: to sway, speed up or stymie one of the Commission's many probes against the behemoths of the US technology sector.