|Photographs uploaded to Pinterest are stripped of their Exchangeable Image File Format (EXIF) data.
This "metadata" is part of a photograph's copyright management information. Digital camera will automatically record a long list of parameters for each photograph, from aperture to date the image was taken. Using the computer interface provided with their camera, photographers can also program their camera to add their name to this information. It's important to learn how to add one's name to one's camera; since 2011, EXIF data is crawled by Google and is searchable in Google Image. If the EXIF data on a photograph displayed on the internet is intact, you should be able to find it by searching for your name in image search.
You can check the EXIF data on your own images using one of the many EXIF viewers available online. You can view the data for an image on the web, or from an image saved to your computer.
Similarly, you can remove the EXIF data yourself by using an online service.