In advance of Congressional hearings today, executives from Google, Facebook, and Twitter have submitted various statements summarizing progress they’ve made in combatting electoral manipulations, while at the same time pledging to do more.

Though these companies have suffered numerous body blows to their reputations over the past couple of years, their leaders insist that they can eventually become forces for good. At the same time, they took pains to note: “Hey, this internet stuff is really hard.”

“I hope my testimony before the Committee will demonstrate the challenges that we are tackling as a global platform,” said a statement submitted by Twitter CEO Jack Dorsey . “Twitter is approaching these challenges with a simple question: How do we earn more trust from the people using our service? We know the way to earn more trust around how we make decisions on our platform is to be as transparent as possible.”

Dorsey and Facebook COO Sheryl Sandberg will appear in the morning before the Senate Intelligence Committee hearing to discuss how foreign actors have been manipulating social media. In the afternoon, Dorsey will testify at a House Energy and Commerce committee hearing that will focus on content moderation. It was the latter committee that posted Dorsey’s opening statement online.

The New York Times reported that it had snagged a copy of Sandberg’s opening statement. According to the paper, she will say: “We were too slow to spot this and too slow to act. That’s on us. We’re getting better at finding and combating our adversaries, from financially motivated troll farms to sophisticated military intelligence operations.”

Meanwhile, Facebook CEO Mark Zuckerberg wrote an op-ed in the Washington Post in which he promises the company is doing more to combat fake news and manipulation.

“When you build services that connect billions of people across countries and cultures, you’re going to see all of the good that humanity can do, and you’re also going to see people try to abuse those services in every way possible,” he wrote. “Our responsibility at Facebook is to amplify the good and mitigate the bad.”

Zuckberberg noted the company has had success combatting efforts in manipulation in other more recent elections and that advances in AI have helped Facebook block million of fake accounts. And he pointed out that the company is teaming up with other tech companies to coordinate responses.

While Google is not testifying at the hearings, the company did post a statement it gave to the Senate committee.

“We believe that we have a responsibility to prevent the misuse of our platforms, and we take that very seriously,” wrote Kent Walker, Google’s SVP of global affairs and chief legal officer. “Our efforts in this area started many years before the 2016 election. We work to detect and minimize opportunities for manipulation and abuse, constantly tackling new threats and bad actors that arise. Google was founded with a mission to organize the world’s information and make it universally accessible and useful; the abuse of the tools and platforms we build is antithetical to that mission.”

Dorsey addressed another point of contention in his statement: complaints by Conservatives that Twitter (and other social media sites) have a bias against right-wing voices.

“Let me be clear about one important and foundational fact: Twitter does not use political ideology to make any decisions, whether related to ranking content on our service or how we enforce our rules,” Dorsey wrote. “We believe strongly in being impartial, and we strive to enforce our rules impartially. We do not shadowban anyone based on political ideology. In fact, from a simple business perspective and to serve the public conversation, Twitter is incentivized to keep all voices on the platform.”