Both the DOJ and FTC have declined to comment on the rumor.

It wouldn't be shocking to see action. The FTC created a task force precisely to investigate antitrust issues in the tech industry, and companies like Google have faced antitrust crackdowns in Europe. Whether or not anything happens in the near future, this could also serve as a warning to Amazon and Google -- officials are wary of their behavior, and it might not take much to prompt formal investigations.

As it is, there are longer-term concerns. Democratic presidential hopefuls have more than once suggested that tech companies might need breaking up, some making that point more forcefully than others. The division of responsibilities between the DOJ and FTC could prove important if there's a change in US leadership that leads to stricter controls on tech firms.