Facebook, Google and Twitter faced Congress in the past weeks to answer questions about how Russian companies and troll farms spread deceptions and inaccuracies before and after the 2016 U.S. presidential election. The digital tech companies were also asked if there was evidence of collusion between the Russian actors and the Trump campaign, and Google was asked specifically about its commercial dealings with a Russian broadcaster that, say federal intelligence agencies, is a Kremlin propaganda outlet.

The Wall Street Journal reports on the highlights of companies’ testimony, including questions they did not answer. Facebook said that the Internet Research Agency, a Russian troll farm, “used Facebook’s tools to promote rallies, protests and other events across the U.S. that cut across ideological lines.”

Thirteen pages IRA created “attempted to organize 129 events,” which were “viewed by 338,300 unique Facebook accounts,” with “62,500 marked they were attending one of the events and 25,800 accounts marked they were interested.”

Facebook gave conflicting answers as to if there was evidence of a collusion between the Trump campaign and Russian actors, saying first that it found “what appears to be insignificant overlap,” and later that it can’t “substantiate or disprove allegations of possible collusion.” Facebook did say it had “no evidence that the IRA used U.S. voter registration data to target ads on the platform.”

Although researchers estimate that 10 percent to 15 percent of Twitter accounts are spam or bots, the company countered that fewer than 5 percent fall into that category, pointing to its own researchers and their access to user data. The Russian state news agency, RT, dubbed “the Kremlin’s principal international propaganda outlet” by intelligence officials, relied on YouTube, Facebook and Twitter “as primary distributors of its content.”

Google “told the Senate that it now describes RT’s relationship with the Russian government in search results” and is “working on disclosures to provide similar transparency on YouTube.”

Recode reports that, in response to a pointed question from Senator Kamala Harris (D-California) as to whether gubernatorial races were compromised, Google and Twitter informed the U.S. Congress that, “they did not spot any attempts by Russian agents to spread disinformation on their sites when voters headed to the polls in Virginia and New Jersey last year.”

Facebook later told Recode that, “it isn’t aware of such abuse on its platform, either,” and added only that, “we have learned from the 2016 election cycle and from elections worldwide this last year.” Twitter reports it is “detecting and blocking approximately 450,000 suspicious logins each day” and has “identified and challenged an average of four million suspicious accounts per week.”

Senator Mark Warner (D-Virginia), who sits on the intelligence committee, is seeking to prevent a replay of the 2016 elections in the upcoming 2018 mid-term elections, proposing regulation of political ads on the social media sites.