American multinational technology company Google logo seen at Googleplex, the corporate headquarters complex of Google and its parent company Alphabet Inc. (Photo by Alex Tai/SOPA Images/LightRocket via Getty Images) The Justice Department is expected to file a lawsuit Tuesday alleging that Google has been abusing its online dominance in online search to stifle competition and harm consumers.The litigation marks the government’s most significant act to protect competition since its groundbreaking case against Microsoft more than 20 years ago.The suit could be an opening salvo ahead of other major government antitrust actions, given ongoing investigations of major tech companies including Apple, Amazon and Facebook at both the Justice.