Hey, Yes adding copyright Logo will protect your photos from being copied.
If you are using an android device, I have a suggestion you to use this app named "Logext: Add Logo watermark and Text sign to photos" from Google Play Store.
The application put copyright logo on picture to safeguard your photo. you can also add copyright trademark logo to the photos with this application. It also allows you to watermark your photos.
It is the best app I have used.
Hope, this helps you out!
Today many people will add a copyright logo to the photos they sell online or use in their blog or website. The Watermark is used to protect your images. However, this isn't always the way it works. People have found ways to delete these logos or Watermarks and still use your photo. Basically, all you can do is this:
I think adding a copyright tag can get you on the safer side while sharing your photos online. But that depends on your what kind of copyright logo it is.