Android Developers Blog reports that "Google used their "kill switch" for the first time — "a security researcher created two free apps, which intentionally misrepresented their purpose in order to encourage user downloads, but they "weren't designed to be used maliciously," and didn't have permission to access private data — or system resources beyond permission.INTERNET. As the apps were practically useless, most users uninstalled shortly after downloading them. The researcher voluntarily removed these apps from Android Market, we decided to exercise our remote application removal feature on remaining installed copies to complete the cleanup," writes Google.
"remote app removal feature is one of many security controls Android possesses to help protect users from malicious apps. In case of an emergency, a dangerous application could be removed from active circulation in a rapid and scalable manner to prevent further exposure to users. While we hope to not have to use it, we know that we've capability to take swift action on behalf of users' safety when needed."