 Alphabet Inc.s GOOGL, -0.43 GOOG, -0.38 Google and Nvidia Inc. NVDA, 3.19 have raised concerns with regulators that Microsoft Corp.s MSFT, 1.16 proposed 69 billion acquisition of Activision Blizzard Inc. ATVI, -0.13 could give the tech giant an unfair competitive advantage, according to a new report. 