Since the acquisition, Onavo was frequently classified as being spyware, as the VPN was used to monetize application usage data collected within an allegedly privacy-focused environment.

In February 2019, in response to criticism over a Facebook market research program employing similar techniques (including, in particular, being targeted towards teens), Onavo announced that it would close the Android version of Protect as well.

[12] The solution Facebook engineers proposed to Zuckerberg's directive was to use Onavo, which allowed the company to read network traffic on a device prior to its being encrypted, thereby giving the company the ability "to measure detailed in-app activity" and to collect analytics on Snapchat app usage from devices on which Onavo was installed.

[12] It did this by creating "fake digital certificates to impersonate trusted Snapchat, YouTube, and Amazon analytics servers to redirect and decrypt secure traffic from those apps for Facebook’s strategic analysis.

[27][28] In July 2023 Australia's Federal Court ordered Facebook's owner to pay A$20 million for failing to disclose how Onavo would be used to collect data, as well as A$400,000 to cover the ACCC's legal fees.

[31] In response, Nissan Slomiansky, chairman of the Constitution, Law, and Justice Committee, asserted that the sudden reversal was prompted by pressure from "large forces" with vested interests.

[32] Media reports speculated that Jordana Cutler, Netanyahu's former advisor who serves as Facebook's Public Policy Director in Israel, played a pivotal role in influencing the Prime Minister's decision to block the legislation.

[33] Lawyer Itai Leshem, claimed during his campaign in the 2024 Israeli Labor Party leadership election, that this was part of an ongoing alleged bribe between PM Netanyahu and Facebook.

[38] In 2016, CEO Mark Zuckerberg tasked Facebook employees with developing a means to decrypt the network traffic of the video sharing app Snapchat for analytics purposes, citing "how quickly they're growing".

A method of intercepting the traffic was developed and proposed by the Onavo team; Facebook internally referred to its analytics scheme as "Project Ghostbusters"—an allusion to Snapchat's logo and the film franchise.

[43][44][45] On January 29, 2019, TechCrunch published a report detailing "Project Atlas"—an internal market research program employed by Facebook since 2016.

"[51][52] Massachusetts Senator Ed Markey announced that he would introduce a bill to strengthen the Children's Online Privacy Protection Act (COPPA), and said that it "is inherently manipulative to offer teens money in exchange for their personal information when younger users don’t have a clear understanding how much data they're handing over and how sensitive it is.

Addressing concerns with previous incarnations of the research app, Study does not use a VPN or a root certificate to conduct its data collection.