From the Kickstarter page:
The Noun Project’s mission is to share, celebrate, and enhance the world’s visual language. Our goal is to collect and organize all the symbols that form our language into one easy-to-use online library that can be accessed by anyone. All the symbols on our site are completely free to download, and can be used for design projects, architecture presentations, art pieces - just about anything.
One can only hope that they will soon provide an easy way to "download all" and search, rather than having to scroll through the page endlessly to find what you want. According to the video on their Kickstarter page, they will add more such features soon.