While searching for these URLs is not illegal in most jurisdictions, interacting with the devices (such as attempting to guess passwords or controlling the camera's pan/tilt functions) can cross legal boundaries into unauthorized access.
Tells Google to look for specific text within the URL. inurl+viewerframe+mode+motion+upd
Never use the "admin/admin" or "12345" passwords that come with the device. While searching for these URLs is not illegal