Gary has Google Fi and would like to block calls by area code. Leo says that robocalls are the bane of smartphones and studies show that by next year, up to 80% of all calls will be robocalls to cell phones. Blocking an area code is extreme, but Leo says that Google is working on a technology that will route robo calls, or require them to identify themselves. Google Voice already does that. There's also an app called PreFixer which will block a number by prefix. Another interesting app is Signal Spy, which would let him choose the network he wants with Google Fi.