Since the 2016 U.S. presidential election nearly a year ago, there has been increasing scrutiny of how Russian-backed operatives used accounts on Facebook, Google and Twitter to try to influence its outcome.
Executives from those companies appear before at least three congressional hearings starting Tuesday, facing questions from lawmakers about what happened and how they plan to respond.
What happened on the internet companies' services during the 2016 election "was the undermining of our political process," said Ann Ravel, a lecturer at the University of California-Berkeley's law school and a former chair at the Federal Election Commission, the federal agency that enforces campaign finance law.
The congressional spotlight on the internet marks a shift in how lawmakers and the public think of the global communications network, observers say.
View of the internet
For years, the internet was viewed as "an egalitarian force, basically giving voice to the voiceless," said Nate Persily, a Stanford University law professor.
The 2016 election, with Russian-backed operatives reportedly placing political ads on social networks or posing as Americans talking about hot-button issues, changed that utopian view of the internet.
"We realized that once you allow anyone to speak to as many people as they want no matter when they want, that enables certain types of speakers who hold undemocratic speech," Persily said.
On the streets of San Francisco, people interviewed echoed frustrations heard around the country that little is known yet about how and why Russian-backed actors used internet firms.
But some say tech companies should take responsibility for what happens on their services and play more of a monitoring role than they have done.
"Social media is accessible to everyone," peer counselor Moinnette Harris said. "People can engage in it or put whatever they want on there, whether it's true or false."
Lia McLoughlin, a stay-at-home parent, said, "I think Facebook has a responsibility. ... If you know that there's something that is affecting our democracy, and if you have any idea that it might be fake, there is a reason to stand in there. It's our democracy."
Facebook and other companies share responsibility if their services were used by foreign agents, said Christian Simonetti, an administrative assistant. But any new rules or penalties the internet companies face should be done "without infringing on people's democratic rights to express themselves," he said.
Law lecturer Ravel said that congressional leaders and regulators should require that internet companies be transparent about who is using their services for political ads, something that billboards, TV stations and newspapers have to do.
In recent weeks, some of the companies have vowed to make changes in reaction to the scrutiny. Twitter and Facebook have said they will do more to make political advertisements more transparent.
Twitter also banned RT and Sputnik, two Russian-backed media companies, from advertising on its site.
But almost everyone agrees it would be harder to regulate — for the government and internet firms — so-called "issue-based ads," which are about hot topics such as gun rights and gay marriage. Those ads may not be tied to a specific candidate or ballot measure.
Even harder would be fake Facebook or Twitter accounts created overseas but purporting to have been created by people living in a targeted community.
"There is currently no clear industry definition for issue-based ads," Twitter said in a blog post.
How the U.S. navigates these issues will matter to the rest of the world, Ravel said.
"It's important for the United States to be a leader to balance innovation we want from the internet for people to speak openly on the internet," Ravel said, "yet to do something to prevent the intervention in the election."