More than 500 Android apps were found to secretly contain spyware, resulting in their removal from the Google Play store, according to a report.

According to ZDNet, the apps were “collectively downloaded over 100 million times from the Google Play store,” and “could have been used to secretly distribute spyware to users, thanks to a malicious advertising SDK (software development kit).”

“Ultimately, the ad network has the potential to turn more than 100 million Android phones into malicious spying devices, putting the privacy of users and their employers at risk,” they explained. “Igexin, which is Chinese in origin, promotes services that claim to leverage data about people, such as their interests, occupation, income, and location for the benefit of advertising. Lookout researchers began investigating Igexin when reviewing other apps that communicated with IP addresses and servers known to have distributed malware. They found that many of the apps’ requests were being made to an endpoint used by the Igexin ad SDK.”

“Alarm bells rang because this sort of traffic is commonly used by malware distributors, who specialize in hiding their malicious payloads within apps that appear to be legitimate,” ZDNet continued. “The app developers would have been unaware of the SDK’s abuse of app permissions for data collection: this functionality is not immediately obvious, and those behind the malicious code can alter it at any time.”

Last week, the Google Play store also removed the app for free speech social network Gab, which had already been up for several months, citing “hate speech” on the platform.

“This should come as no surprise to anyone paying attention. The Silicon Valley ideological echo chamber is real,” claimed Gab CEO Andrew Torba to Breitbart Tech. “They have chosen to not support a free and open internet.”

“The alt tech revolution has begun,” he continued. “We ask developers who believe in our mission of free speech and individual liberty for all to rise up, speak out, and build free speech friendly products against the totalitarianism occurring in the tech industry.”

Gab had previously extended a job offer to James Damore, the former Google employee who was fired from the company after he published a viewpoint diversity manifesto, and have subsequently started a legal fund in an attempt to take on Silicon Valley censorship.

Charlie Nash is a reporter for Breitbart Tech. You can follow him on Twitter @MrNashington and Gab @Nash, or like his page at Facebook.