The cafe where Riley and friends sat and hacked in episode 4x09 is a real cafe in Atlanta. They didn't even change the name.
Ginseng Cafe, 52 Broad St NW, Atlanta, GAThis first image shows us the front of the cafe. There have been some small changes made to the front window since filming, but the following images help confirm the location
In this image we can identify the noodle soup restaurant we see in the background of the shot.This shows us where they sat up to film the scene.[SIZE=7]