Description: Consumer Reports submitted a letter to the Senate Antitrust Subcommittee for the record in its hearing examining whether Google’s online advertising practices are harming competition and consumers. We highlighted the potential for Google to use its dominant position in all layers of the pipeline connecting sellers and advertising outlets to restrict options and entrench its power. We noted that the familiar harmful effects of market power are augmented by the vast troves of data that Google collects on consumers and sellers and the interactions between them.