Most of these cameras are not "hacked" in the traditional sense. Instead, they appear in search results because of:
Use unique usernames and complex passwords for every device. If you'd like to dive deeper into this, let me know: inurl viewerframe mode motion link
Manufacturers release patches to close security holes. Most of these cameras are not "hacked" in
Manually manage your port forwarding to avoid automated exposure. inurl viewerframe mode motion link
Access your home network via a secure tunnel rather than exposing the camera directly to the web.
If you are worried about your own hardware showing up in search results, follow these steps:
This feature can automatically open ports on a router, inadvertently shouting the camera’s location to search engine crawlers. The Privacy Implications