It's a demonstration of google dorking. Construct a google search term that returns attackable hosts. Skip past the first few results, then you'll see a list

It's a demonstration of google dorking. Construct a google search term that returns attackable hosts. Skip past the first few results, then you'll see a list of likely easily-hackable home routers. If you were to try user/pass combos like "admin"/"admin" on these results I bet you'd have successful logins on several of them. Don't actually do this (seriously, the penalties aren't light), the demonstration of the search results is enough to make the point.