The early moves from the government's twin antitrust agencies mark the latest attempts by U.S. regulators to better supervise tech giants. Earlier this year, the FTC established a special "task force" that it said would monitor tech and competition, including "investigating any potential anticompetitive conduct in those markets, and taking enforcement actions when warranted."
For years, though, the European Union has taken the lead in probing whether Silicon Valley too easily stamps out rivals to the detriment of web users. EU officials are actively investigating Amazon and have repeatedly fined Google for violating its antitrust laws.
Antitrust also has become an early flash point among Democrats vying for the White House ahead of the 2020 election. Sen. Elizabeth Warren recently has threatened major investigations of Amazon, Apple and Facebook. This week, she offered early support in response to the news that the DOJ could bring such a probe against Google.
Politicians have long raised concerns that Amazon's dominance in online retail - as well as its growing reach across a broad variety of business fields - has given it too much power. It holds sway over third-party sellers on its site, who pay for advertising to compete against first-party and private-label sales by Amazon. And its low prices have helped it draw customer spending at the expense of brick-and-mortar competitors.
The e-commerce giant sells roughly half of all online goods in the United States, but it comprises a much smaller portion of total retail sales. It has also expanded into other areas, such as cloud computing with Amazon Web Services and grocery sales with the acquisition of Whole Foods, a deal the FTC allowed to proceed in 2017.
With Google, its chief critics contend the company has acted illegally to protect its massive footprint in search and advertising and its newer ambitions ranging from smart thermostats to self-driving cars. Previously, the FTC investigated Google but closed the matter in 2013 without breaking it up or forcing it to make major changes to its business practices.
"This should be a wake up call to both Google and Amazon to behave themselves because it at least shows that the Justice Department and FTC are thinking about them," said Gene Kimmelman, the president of Public Knowledge, a Washington-based consumer advocacy group.