Irish government head Taoiseach Leo Varadkar, who backs legal abortion, welcomed the move from Google.
Maria Steen of the Iona Institute, however, said Google's decision was "an attack on the integrity of the referendum" and "a blatant attempt to silence debate in Ireland."
In Leahy's view, pro-repeal leaders "wholeheartedly welcomed and applauded" Google's decision, and their reaction shows that the decision favors their side.
The Irish Times suggested that companies have become afraid that if voters reject the referendum, they will face blame and further scrutiny for allegedly influencing elections.
Facebook also announced a policy change, but said that it would be canceling only foreign-funded ads related to the referendum.
John McGuirk, a spokesman for the Save the 8th campaign, welcomed Facebook's decision and suggested it would affect a very small percentage of ads. However, he argued that Google's move against domestic advertising was driven by fears of pro-abortion rights groups that they would lose the vote and therefore they wanted to limit voter information.
Irish law largely restricts foreign funding of political campaigns, but there is little legal oversight of social media.
Financier and philanthropist George Soros' Open Society Foundations and its pro-abortion rights grantees have already run afoul of Irish political finance rules.
Abortion Rights Campaign Ireland had received about $29,500 from the foundations in 2016, but returned it later that year after being contacted by The Republic of Ireland's Standards in Public Office Commission, which warned that the organization could be reported to the national police.
As of December 2017, Irish officials were in talks with the Irish Family Planning Association, which received $150,000 from the Open Society Foundations in 2016, because of possible violations of election laws on political funding.
That same month, officials ordered Amnesty International to return $160,000 to the foundations because the money violated Irish law barring foreign donations to third party groups seeking to influence the outcome of a referendum campaign. Amnesty International has challenged the opinion.
However, backers of repeal have similarly tried to make an issue of overseas advocacy from U.S. pro-lifers.
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The Washington Post, citing the Transparent Referendum Initiative, said Facebook ads have appeared from Live Action, the Radiance Foundation, and the New York City-based Expectant Mother Care/E.M.C. FrontLine Pregnancy Centers.
In March, the online weekly newspaper Dublin Inquirer interviewed Chris Slattery, founder and CEO of the New-York based pregnancy centers, about the sponsorship of those ads.
"I was requested by Irish pro-life activists to stir up Americans to stand with them to support the Eighth Amendment," he said, reporting that he had spent "a few hundred dollars" boosting posts to his "friends in Ireland."
Slattery voiced surprise that a journalist was calling him about the ads.
Facebook has said it has built relationships with political parties, groups representing both sides of the referendum, and the Transparent Referendum Initiative, "who we are asking to notify us if they have concerns about ad campaigns."
"We will then assess and act on those reports," Facebook said May 8. "We will also be using machine learning to help us with this effort to identify ads that should no longer be running."