A small change in Android 4.2.2 has left one of the biggest ad-blocking app on Android basically dead in the water. Adblock Plus is one of the web's most popular ad-blocking tools, and has been available for Android since November of last year. So, why has Google effectively killed it? Security issues.
Adblock Plus relies on the internet permission in Android to function, but it relies on a rather specific subset of that permission in order to work: the ability to automatically set a device's proxy server to 'localhost.' As is pointed out on a thread in the Android issues section of Google Code, this is a pretty serious security flaw.