(Reuters) The U.S. Justice Department said on Tuesday it was opening a broad investigation of major digital technology firms into whether they engage in anticompetitive practices the strongest sign the Trump administration is stepping up its scrutiny of Big Tech. The review will look into whether and how market-leading online platforms have achieved market power and are engaging in practices that have reduced competition stifled innovation or otherwise harmed consumers" the Justice Department said in a statement. The Justice Department did not identify specific companies but said the review would consider concerns raised about search social media and some retail services online" an apparent reference to Alphabet Inc Amazon.com Inc and Facebook Inc and potentially Apple Inc. A Justice Department spokesman declined to provide a list of companies that would be scrutinized.