I remember using those when I was just a kid! I'm pretty sure that there was some sort of search term or operator that I used to find them through Google.

I used to have a huge list bookmarked, and they weren't just on famous landmarks. It was actually kind of creepy because some were located in offices, small businesses,etc.

One time a friend and I constantly rotated one of the office cameras until a guy got up from his desk and covered the lens with a piece of paper. I'm guessing that the owners didn't realize that they were accessible by anyone with an Internet connection...