I've been doing it for the past few days. It's really easy, so here is a simple explanation.
First make a shodan account.
Then type in this:
>Set-Cookie: iomega=
Then start clicking on the links. If you are on Firefox you will get a message that says "This Connection is Untrusted." At the bottom of that message will be a button that says "Add Exception." Click on that and there will be a pop up. At the bottom of that pop up there will be a check box that says "Permanently store this exception." UNCHECK that box. Then click the "Confirm Security Exception" button.
Now you will come to a window that should have two tabs. One that says "Slideshow" and one that says "Content." Sometimes you wont come to this however. If you end up on something other than this window (it may be a log in page, or a link to something other thing) just close the window and try a different link. You want to click on the "Content" tab. This is where you need some luck. If they have left their folders in their hdd open you will see them listed. Usually these are their "Pictures," "Music," "Documents," and "Movies." Click on whichever one you want and you will be taken to a link where you can explore what they have left open. However some people are not sharing anything over the cloud. For those people the "Content" tab will either be blank or say "Nothing is currently being shared." If you get those then you just need to close the window and try again.
If you followed all of the instructions then you will have success. Congratulations. Most people have uninteresting hdds, but every once in a while you come across something interesting. It could be a project they are working on, pics at cool locations, or just good old fashioned nudes. I've read that you probably want to set up a proxy and a sandbox, but I am /tech/ illiterate and do not know how to do this so I have not.
Also remember that you can add filters like which country, state, and city you want to narrow your search down to in shodan. It can be interesting to see what different parts of the world save on their computers. I've found that a surprisingly large amount of Canadians are weebs, and that asians love to take pictures of really random things.
>pic related
I made it from some pic I got from doing this.