The instant you take an image it becomes copyrighted by you the photographer. When you upload a image or other file like video here by default you are granting this site permission to use and display this material. What I couldn't do with it is use the image or file in another context like compile many images into a photo book for sale. If I wanted to do that I'd have get the permission of each person who's images I wanted to use.
I have a number of photos I would like to post but don't want to find them elsewhere on the net in the future.
There is really nothing I can do to prevent his, if someone finds your image here they can easily save it and use it elsewhere. The only sure fire way to protect the image is to not upload it. I would suggest adding a small copyright using an image editor or Irfanview which can do them in batches if you want to add the copyright to many images at once. You can also add a copyright to the EXIF/IPTC meta data. Neither of these is sure fire and easily erased, cropped etc.
Could community photo albums on the forum require registration to view?
The idea of this site is to bring people of common interests together, most find it via a Search Engine through previous topics so this would be counter to what I'm trying to do here.
..... someone only searching the net for photos.....
At this point the images are not indexed by any Search Engines because I don;t allow them too but that will change in the future.