The photographer owns the photo unless you buy it from him or he gives it to you. You can use the photo as long as it's not for profit and there's not much a photographer could do even if he cares. I only post 1/4 size images on the internet, which are huge, but offer people the full size photo if they want it. I don't charge, but if I did this would protect me. Someone could steal the photo, but not the best version.
Here's what an attorney says:
The copyright in the work of authorship immediately becomes the property of the author who created the work. Unless the photo is a work made for hire, then the other person – not you – owns the copyright. However, depending on the circumstances, you likely have an implied license to use the photograph for personal uses. For example, if you ask someone to take a shot of your family on vacation, you could do things such as print the photo for display in your home, post the photo on your personal Facebook page, or share the photo via email with friends or family. But you probably wouldn’t have the right to enter the photo into a contest or license it for commercial purposes.
