The US Department of Justice opens up a broad antitrust review in major technology companies, as criticism of companies' growing reach and power is getting hotter.
The investigation will focus on increasing complaints that companies are losing competition illegally.
"The department's review will consider the widespread concerns expressed by consumers, businesses and entrepreneurs for search, social media and some online retail services," the Department of Justice said in a statement.
"Without discipline meaningful market-based competition, digital platforms can work in ways that do not meet consumer demands," lawyer Makan Delrahim from the antitrust division added.
The review will examine the practice of online platforms including Facebook, Alphabet's Google, Amazon and Apple.
The investigation comes from lawmakers' calls, including democratic presidential candidates such as Elizabeth Warren, that companies should face more scrutiny.
Lazy week, Facebook, Google and Amazon met a grilling before the House's sub-committee for antitrust, commercial and administrative legislation over their teams in markets including digital advertising, e-commerce, and cloud computing.
Lawmakers questioned Amazon about the fees it imposes on third-party sellers on the platform and whether this creates a power monopoly. They also questioned Facebook executives over the practice of targeting startups for the acquisition and copying of features of companies that refuse to be acquired.
Lawmakers also grilled Facebook this month over the plans to launch a global cryptocurrency, called Libra. During the hearing, Senator Sherrod Brown of Ohio said that Facebook showed "great arrogance" in the attempt to launch a digital financial service following a series of major privacy scandals.
In July, the Federal Trade Commission approved a $ 5 billion fine against Facebook for its handling of user data around the Cambridge Analytica scandal in 2018.
"Facebook is dangerous," said Brown, and resembled the company with a toddler playing with matches. "It has burned the house repeatedly and called all attempts for a learning experience. Do you really think people should trust you with bank accounts and money? "
The investigation at the Ministry of Justice is already underway, Wall Street Journal reported Tuesday. The department hosted a private presentation from critics of major technology companies, who went lawmakers through concerns and arguments to break up the companies.
Facebook, Alphabet, Amazon and Apple did not immediately respond to requests for comment.