Single post in Regarding Art Theft

Does this apply to templates in general, I sometimes use other peoples art for templates, I always ask permission, but I get rid of my inbox messages on deviant art so there isn't always proof anymore. I always credit them on the template and link back to them. So in this case what would I have to do, it would be a royal pain to have to add those links and that screenshot to the template each time I use it, or if I make a template for a contest etc.