Facebook’s ad data may put millions of gay people at risk

Technology 24 August 2019
Someone looking at Facebook
If you “Like” a Facebook page, the data is used to record your interests


Millions of gay people living in countries where homosexuality is outlawed could be put at risk by Facebook’s advertising practices. This is because the firm allows advertisers to target people on the basis of their interests, including sexual ones.

Ángel Cuevas Rumín at Charles III University of Madrid, Spain, and his colleagues analysed the list of options available for targeting adverts on Facebook. They found that about 2000 of the options would be classed as “sensitive” information under Europe’s recent GDPR data protection law. These include a person’s politics, race or sexuality.

Some two-thirds of Facebook users in the 197 countries and states the team looked at were tagged with at least one such preference, accounting for a fifth of the overall population.


In Saudi Arabia, where homosexuality can be punished with death, the team found in February that 540,000 people were labelled as having an interest in homosexuality. The team revisited that number in August and it had nearly doubled to 940,000 people.

Overall, Cuevas’s team found that there were more than 4.2 million people tagged as interested in homosexuality living in countries where homosexuality is illegal. These people could be targeted using Facebook’s ad tools.

While there is no suggestion that anyone has been identified or killed as a result of this practice, such information could be used to identify people and collect information on them. For example, an advert directed at a particular group could offer a prize to people if they enter their personal details.

Facebook says that just because someone shows an interest in something doesn’t mean they have that attribute. You could like a page about gay men, for example, without being a gay man yourself. However, there is likely to be overlap between the two groups.

“The interest targeting options we allow in ads reflect people’s interest in topics, not personal attributes,” Facebook told New Scientist. “People can’t discriminate by excluding interests such as homosexuality when they build an ad.” The firm says it recently removed more than 5000 targeting options.

Collecting such data is a legal grey area. In Europe, there are stronger legal protections for sensitive data than there are for other types of personal data. However, data protection experts are torn over whether Facebook is breaking any laws.

“Facebook is in the wrong for sure, as far as EU data protection law is concerned,” says Ed Boal at Stephenson Law in Bristol, UK. Sandra Wachter at the Oxford Internet Institute, UK, isn’t so sure. “If the argument being made is nobody is inferring sexual orientation but assuming an interest in sexual orientation, that brings us to an unclear legal perspective,” she says. “We need to broaden data protection in a more sensible and holistic way.”

Reference: arXiv, arxiv.org/abs/1802.05030

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