The European Union could soon ban targeted online political advertising using sensitive personal data without user consent under new European Commission proposals published on Thursday.
"Elections must not be a competition of opaque and non-transparent methods," said commission Vice President Vera Jourova in a press release.
"People must know why they are seeing an ad, who paid for it, how much, [and] what micro-targeting criteria were used," said the commissioner whose portfolio covers values and transparency.
The proposals come after years of concern that voters in the EU are vulnerable to manipulation from hostile actors on social media.
Jourova told journalists in Brussels that the Cambridge Analytica scandal provided a "glimpse" into the risks posed by targeted online advertising.
The data analytics company was accused of harvesting the Facebook data of millions of users for work aiding the pro-Brexit campaign as well as former US president Donald Trump's 2016 White House bid.
Under the proposed regulations, targeted political advertisements based on sensitive data like sexual orientation and religious beliefs are to be banned, unless the user explicitly consents.
In addition, new transparency labels must show social media users who financed and by how much the political advert they are seeing. The label also needs to explain the relevant connection to current political events like referendums or elections.
The commission aims for the rules to be in place by 2024.
A recent Eurobarometer survey showed that nearly four out of ten Europeans have been exposed to content where they could not easily determine whether it was a political advertisement or not.