Both sides in the upcoming abortion referendum are using social media ads to target voters, but it is sometimes difficult to find out the origin of the sponsored content.
Campaign groups on both sides are supposed to register with the Standard in Public Office.
There are regulations around donations, and campaign groups are not allowed to receive funds from foreign donors.
Dr Jane Suiter (pictured), director of the Institute for Future Media and Journalism at Dublin City University, said: "Online advertising is completely unregulated and is wide open to abuse.
"Facebook as a platform should be regulated so that it is responsible for ads it carries."
While foreign donors are not supposed to participate in the campaign, there is little to stop them paying for political posts online.
Among the anti-abortion ads targeted at Irish voters are posts promoted by the Karen Gaffney Foundation, based in Portland, Oregon, and Expectant Mother Care, based in New York.
While advertising by referendum campaigners is banned on television stations, there are no such limitations on online videos.
Many of the videos produced for the No side of the campaign have slick production values.
The Save the Eighth Campaign is using Kanto, a British firm that worked on the Brexit referendum during its campaign.
The consultancy was founded by a former executive of Cambridge Analytica, Thomas Borwick.
On its website, Kanto says: "We help harness the power of data and technology to empower your supporters, engage the public and inform your strategy."