You could put your own personal watermark in the corner of the image which doesn't deface the entire image and links back to you, You can still turn off downloads without displaying the deviantart watermark, people can only download your photo's in high resolution if you allow them, The deviantart watermark doesn't even link back to you, so people won't share your images with friends, put them in features, they won't take the time to browse your gallery because all your photo's will have the same logo
I wouldn't worry so much about having them 'stolen' - they will always be yours and you can feel proud if someone wants to share them or display them, if you put your personal watermark in the corner people will be like, ima check out this person, So it's beneficial to you.