If so, you may have a lot more to lose than the few minutes it takes to add the information. Attach your name, copyright status, and caption information to every one of your images that go public/ online.
This is easily done in programs such as Photoshop in the menu bar under File > File Info. Or in Bridge under the super secret section called "METADATA" menu. If you set it up right in Photoshop & Lightroom, this can be done automatically, or in large batches in Bridge. Be sure to include your contact info, email address, and webpage + note yourself as the copyright owner- if it's your photo.
WHY bother? well, it IS possible that an Art Director/ Photo Editor will come across one of your images, and wanting to use it for a project, they can’t or won’t if there is no information at hand about the source of the photo. If you have not provided contact details in the metadata, another photographer’s work will be chosen over yours. Or worse, your image gets used in the project with no credit or compensation to you. Take ownership of your images by making the time to enter metadata.
Why would you not?!