Senior Facebook engineers say no one at the company knows where your data is kept

• Two Meta engineers were grilled in court about where the company stores all its data on users.
• The engineers didn't know where they could find all a user's data, and they thought no one at the company would know.

Two longtime Meta engineers were grilled about how the company stores and keeps track of user data and revealed they don't believe anyone at the company could compile all the data belonging to a single user, newly unsealed court documents revealed.

The two engineers were questioned during a court hearing as part of a consumer privacy lawsuit centered around the Cambridge Analytica scandal of 2018.

The engineers were questioned in March of this year, but the transcript of the hearing was unsealed recently, as first reported by The Intercept.

The questioning was led by a court-appointed technical expert who was trying to ascertain exactly what information Facebook stores about users and where it is all kept.

One of the engineers was Eugene Zarashaw, whose LinkedIn profile says he is an engineering director at Meta and has worked there for almost nine years. The second was Steven Elia, who is described on LinkedIn as a software engineering manager who has spent 11 years at Facebook.

Previously when asked what information it keeps on users Facebook provided the court with its "Download Your Information" tool, but this was found to not contain all the information the court wished to inspect.

The court-appointed expert asked who at Facebook would be able to answer the question: where is all the information on a single user stored.

"I don't believe there's a single person that exists who could answer that question. It would take a significant team effort to even be able to answer that question," answered Zarashaw.

When pressed about whether user data and activity is stored in ad systems, Elia said: "I would also agree there's not a single individual who would recognize all of these or be familiar enough with all of these."

A spokesperson for Meta told Insider it was unsurprising that individual engineers couldn't identify where all the data for a single user was stored across the company's systems.

"We have made — and continue making — significant investments to meet our privacy commitments and obligations, including extensive data controls," the spokesperson added.

The lawsuit against Meta was filed in 2018 and the company reached a settlement in the case in August, one month before CEO Mark Zuckerberg was due to be deposed.