This is so scary because of the highly politicized nature of Trump's DOJ. This feels like it's all about settling political scores that the right wing has against Google and Facebook's functions as gate keepers against fake news. In fact Steve Bannon announced this attack on tech shortly after the election. It is scary because they're now using the power of the federal government against their political enemies, where does that end? And they see an opening for their nakedly political attack because there is a lot of truth to the anticompetitive market, and liberals like Elizabeth Warren have floated similar ideas.