The antitrust vise tightens on tech

The Justice Department's announcement Tuesday that it will probe the market power of online platforms is the latest sign of deepening trouble in Washington for major tech companies.

Why it matters: Antitrust action is one of the most significant steps a government can take to rein in a company — and Justice's announcement is the kind that can kick off years-long probes.

Details:

• DOJ said it was looking at concerns about major online platforms and how they could be "engaging in practices that have reduced competition, stifled innovation, or otherwise harmed consumers."
• Specifically, it indicated it would look at "search, social media, and some retail services online" — wording that, while non-specific, pointed to Google, Facebook and Amazon.

Flashback: The first indication that DOJ under Attorney General Bill Barr could pursue antitrust investigations against major Silicon Valley companies came earlier this year, when the agency split jurisdiction over competition concerns about tech companies with the Federal Trade Commission.

• Justice took Google and Apple, the FTC took Facebook and Amazon.
• DOJ spokesperson Alexei Woltornist declined to comment on how Tuesday's announcement fit into that arrangement.

The big picture: Support for more aggressive antitrust enforcement has grown on the left in recent years, culminating in presidential candidate Elizabeth Warren's proposal to break up Big Tech.

• President Trump has also been extremely critical of major tech companies over alleged — and unsubstantiated — censorship of conservative voices.
• The House Judiciary Committee is conducting its own investigation of major tech firms with its chairman, Rep. David Cicilline (D-R.I.), saying Tuesday that Facebook, Amazon and Google hadn't adequately answered the panel's questions during a recent hearing.
• Lawmakers are also looking at ways to regulate major platforms over concerns about invasions of privacy, disinformation and criminal activity on the internet.

An antitrust prosecution would be a first for this generation of tech companies, which have benefited from enforcers' practice of identifying market dominance by looking for places where it results in higher consumer prices. Google and Facebook give away most of their services for free.

The bottom line: These are the sorts of investigations that, if they pick up steam, can humble corporate giants and have major implications for the economy.

• The last major antitrust case in the sector was Justice's pursuit of Microsoft beginning in the late '90s.
• Some say the case cowed Microsoft, giving Google the space to be successful and, ultimately, grow into a giant of its own.

Go deeper: For tech, antitrust is a fatal distraction