Billionaire CEO’s from across Silicon Valley have long been critical of President Trump’s immigration policies, now with the latest immigration debate becoming a hot topic, many are directly funding opposition to the administration.

Breitbart News reported recently that a Facebook fundraiser aiming to reunite the children of illegal immigrants with their families and fund bail bonds for illegal immigrants detained at the border has raised approximately $4.5 million in just under a week, with Facebook CEO Mark Zuckerberg and COO Sheryl Sandberg donating sizeable amounts to the fundraiser.

The fundraiser initially planned to raise $1,500, but donations reached $4.67 million by Tuesday shortly after several private donors matched donations up to $250,000 each. Donations have since reportedly jumped above $9 million. The Willners wrote on the page: “We are collectively revulsed at what’s happening to immigrant families on our southern border. In times when we often think that the news can’t possibly get worse, it does — we learned last night that 2,000 children (many of them infants and toddlers) have been separated from their parents in just six weeks under President Trump’s ‘zero tolerance’ policy.”

Zuckerberg has previously funded other immigration causes, such as the FWD.us organization, which pushes for more open immigration laws. The organization’s website reads: “FWD.us is mobilizing the tech community in support of policies that keep the American Dream achievable in the 21 century, starting with comprehensive immigration reform.” FWD.us was founded by Zuckerberg along with other tech moguls such as Microsoft founder Bill Gates, former Facebook President Sean Parker and multiple founders and team members of the file-sharing service Dropbox.

Now many more Silicon Valley CEO’s are stepping forward to attack President Trump’s “zero tolerance” immigration policy. Apple CEO Tim Cook told the Irish Times: “It’s heartbreaking to see the images and hear the sounds of the kids. Kids are the most vulnerable people in any society. I think that what’s happening is inhumane, it needs to stop.” Cook also stated that Apple plans to be a “constructive voice” in the current debate: “I’m personally a big believer in the way to be a good citizen is to participate, is to try to advocate your point of view, not to just sit on the sideline and yell or complain. That will be the approach we will take here. This one in particular is just heartbreaking and tragic.”

An official statement from tech company Microsoft also decried the current situation at the U.S. border saying: “We urge the administration to change its policy and Congress to pass legislation ensuring children are no longer separated from their families.” Cisco CEO Chuck Robbins published a statement urging “the Administration to end immediately the policy of separating accompanied minors from their parents. This practice is cruel and contrary to American values.” Robbins told Fortune Magazine: “Our immigration system is broken, and we need leaders to address the major issues.” Robbins said that separating families at the border “is a moral issue for our country.”

Google CEO Sundar Pichai took to Twitter to express his thoughts, urging the government to find a “better, more humane way” to deal with the immigration issue. Pichai has been a longtime critic of President Trump — Google even created a $4 million crisis fund for immigration cases in 2017, supporting groups such as the American Civil Liberties Union, Immigrant Legal Resource Center, International Rescue Committee, and UNHCR.

The stories and images of families being separated at the border are gut-wrenching. Urging our government to work together to find a better, more humane way that is reflective of our values as a nation. #keepfamiliestogether — Sundar Pichai (@sundarpichai) June 19, 2018

Jeremy Stoppelman, the CEO of Yelp, also took to Twitter to support the social justice group MoveOn and invited people in the Silicon Valley area to join him in a public march to protest current immigration policies:

I hope others from SF/Bay Area tech companies will join me at this march planned June 30. Please also consider donating to one of these great orgs assembled by @dahlialithwick & @mjschlanger: https://t.co/mSiMtgw9ga #FamiliesBelongTogether https://t.co/E5jXu4OSiv — Jeremy Stoppelman (@jeremys) June 19, 2018

Dara Khosrowshahi, the current CEO of ride-sharing company Uber, attacked the Trump administrations immigration policies stating that stories from the border “break my heart” and called the current policies “immoral and just plain wrong.”

As a father, a citizen and an immigrant myself, the stories coming from our border break my heart. Families are the backbone of society. A policy that pulls them apart rather than building them up is immoral and just plain wrong. #KeepFamiliesTogether https://t.co/g2Cu40zvcX — dara khosrowshahi (@dkhos) June 19, 2018

Twitter CEO Jack Dorsey asked his users “what are the highest impact ways to help” the current situation:

Do everything it takes to #KeepFamilesTogether. What are the highest impact ways to help? — jack (@jack) June 19, 2018

While YouTube CEO Susan Wojcicki said that regardless of politics “it’s heartbreaking to see what’s happening to families at the border.”

Regardless of your politics, it's heartbreaking to see what's happening to families at the border. Here are some ways you can help: https://t.co/IFVG6g8AKO — Susan Wojcicki (@SusanWojcicki) June 19, 2018

Silicon Valley has long been opponent of the Trump administration, an article published by Recode in 2017 titled “How Silicon Valley is trying to topple Trump — beginning with a special election in Montana” outlined how the team running the House of Representatives campaign for Democratic politician Rob Quist, “a guitar-toting first-timer in the hunt for Montana’s sole spot,” recruited Jessica Alter, a bay area resident who works to link digital tech companies with progressive candidates and causes. Alter’s company, Tech for Campaigns, aims to act as a go-between for Democratic politicians and Silicon Valley tech activists.

Alter devised the idea for her company shortly after the election of President Trump, frustrated with his actions as president. “The first travel ban, the Muslim ban, put me over the edge, candidly because my father’s family was in the Holocaust, and my grandmother was very active in the Belgian underground,” Alter told Recode. “And I just imagined, what would she do?” Tech for Campaigns now has a network of nearly 3,000 volunteers comprised of data analytics and design experts from many high-ranking Silicon Valley companies such as Facebook, Netflix, Slack, and Salesforce.