Google Voice Global Spam Filtering
Sadly, spam is no longer confined to the email inbox. Robocalls can be a major time-consuming distraction. But just as Gmail's spam filter quite effectively winnows out a lot of junk mail, Google Voice (Google's universal call forwarding/voicemail service) offers tools for discarding these unwanted calls before they ring through. Primary among them is Global Spam Filtering, which immediately discards calls coming from numbers Google has identified as spam sources. Activate it by clicking on Calls in Google Voice's settings.