Well when I was selling a lot of prints a number of years ago the advice I got was
to make a copy of every image I was selling and post them to myself
via registered mail and dont open the envelope leave it sealed as proof
of owning the images before any copies could be made.
over the web I think is a bit more complicated . . . how do you know
if your images are not being used for a magazine in Brazil?
How, Exactly does one copyright a photo and/or protect it once o the web?
By default any image you take is protected by copyright.
As for someone using it – well, best way to prevent that is to use small quality images online, and/or watermark your photos, so that it’s clear that they are yours.
There is no miracle cure to protecting your images and your copyright.
Make sure you watermark the area of interest in the photo.
Simply watermarking the edge of the photo leaves open the option of cropping out the watermark.