Fresh from fighting content filters in the EU, Google is working on the ultimate content filter– which seals the user off in a spam-free bubble. It's a nuisance caller detection feature built into Android, and it could have unintended consequences. The feature, spotted in recent commits to the Android Open Source Project (AOSP), offers to "screen unwanted calls with real-time audio transcription and quick responses". The commits were spotted by sharp-eyed devs at XDA here. Many phone apps already include a blacklist feature and third-party phone apps, such as Drupe and Truecaller, use caller ID to screen unwanted calls.