Facebook reportedly collected the personal information of 187,000 users, including 4,300 teenagers, using a research app which has since been banned from Apple’s app store.

Facebook reportedly collected the private information of as many as 187,000 users before the app was banned from the Apple App Store, according to TechCrunch. In a letter sent to Sen. Richard Blumenthal’s office, Facebook stated that using the app the firm collected data on 31,000 users in the U.S., including 4,300 teenagers; while the rest of the data collected came from Indian users.

In February of this year, Facebook VP of Production, Engineering, and Security Pedro Canahuati, attempted to explain the Facebook Research app and Apple’s decision to remove it from their app store. Canahuati explained in a memo to employees that Apple had revoked Facbeook’s Enterprise Certificate which allowed the company to distribute apps internally outside of its App Store.

Later, Apple restored Facebook’s Enterprise Certificate, but the company was forced to rebuild “a few dozen” apps that employees rely on. Later in the memo, Canahuati defended Facebook’s research methods and attacked the media for its portrayal of the app, but later shut down the research app following intense public backlash.

Apple stated that it was unaware of how many users may have installed Facebook’s app. Timothy Powderly, Apple’s director of federal affairs stated in a letter to lawmakers: “We know that the provisioning profile for the Facebook Research app was created on April 19, 2017, but this does not necessarily correlate to the date that Facebook distributed the provisioning profile to end users.”

Facebook claimed in its letter that its app “specifically ignores information shared via financial or health apps,” but added that “in some isolated circumstances the app received some limited non-targeted content.” A Facebook spokesperson stated: “We did not review all of the data to determine whether it contained health or financial data. We have deleted all user-level market insights data that was collected from the Facebook Research app, which would include any health or financial data that may have existed.”

Sen. Blumenthal told TechCrunch: “After its previous app was rightly taken down and blocked from operating, Facebook moved more quickly to reintroduce a market research product than it has to provide any substantial consumer privacy protections or resolve the significant abuse on its platform. At a time when the company is under investigation for its data practices and anticompetitive actions, the Facebook Study app is at best tone-deaf and ill-considered.”

Read the full letters from tech giants Facebook, Apple, and Google at TechCrunch here.

Lucas Nolan is a reporter for Breitbart News covering issues of free speech and online censorship. Follow him on Twitter @LucasNolan or email him at lnolan@breitbart.com