BuzzFeed has denied that it is recording intimate details that can be traced to individual readers, following a report from a web developer that queried the site's data collection.
Writing on his personal blog, Dan Barker said that the website passes the age, gender and country of users to Google Analytics if the data is available, raising the possibility that it could be cross referenced with quiz questions revealing intimate information.
He said: "Most quizzes are extremely benign: the stereotypical 'Which currently popular fictional TV show Character Are You?' for example. But some of their quizzes are very specific, and very personal."
As an example he cited the quiz "How privileged are you?", which has more than 2 million views and includes questions on whether the user has been raped, attempted suicide, or taken medicine for mental health.
"In other words, if I had access to the BuzzFeed Google Analytics data, I could query data for people who got to the end of the quiz and indicated - by not checking that particular answer - that they have had an eating disorder," Barker said.
He added that he was not certain whether it was possible to link Google Analytics data to his personally identifiable information, which is prohibited by the company's terms of service.
Despite this, Barker argued that the quiz may have received fewer views if the participants were aware their clicks were being recorded and could later be reported on, whether or not the data was anonymised.
Alice Suh, global director of communications at BuzzFeed, said: "The blogpost is missing crucial information. We anonymise all usage data and have strict internal policies around only accessing data in the aggregate form."
The potential for using data in marketing was raised by BuzzFeed earlier this year, with a spokesman from the firm stating the company was in the business of selling "social advertising" as opposed to data.
Summer Anne Burton, managing editorial director at BuzzFeed, told Marketplace: "We're now looking at how to use the things that we've learned for companies' benefit, so they can have their own shareable pieces of content that go viral and that are really associated with their brand."