Flippervolt gathers information about images via two types of image feeds:  RSS and JSON.  These feeds are accessed via web addresses that tell the website (like tumbler.com or reddit.com) that a stream of data should be provided rather than the standard visual webpage that a human would view.    Flippervolt reads the data from these feeds and finds information about the images in them, and then displays those images for you.

If you curate a Tumblr blog, you have the option to turn off the RSS feed for your blog.  If you do not turn it off, then the content of your blog will be accessible to anyone using an RSS reader.  If you post to Reddit, however, we are not aware of a method to prevent your post from appearing in a feed.