Photograph copyright or protection question

I have a question for you guys about your personal photographs, pictures you have taken of your quilts, crafts, etc.  Do you put a watermark or copyright mark on your photos before you put them on your blog or website?  The reason I am asking is that last night I found something that has me more than a little irked.  I was googling images last night for quilted star ornaments and came across one of my own that had been on my Etsy shop a couple of years ago.  I sold that one and made the listing inactive until I get another one made, assuming I still have the fabric.  I clicked on the image (my original picture, my original creation) and it took me to a Flickr account from another person, a site called "paperbilities4you."  I visited this web site and there are things for sale.  I have absolutely no idea why this person added my picture to their Flickr unless they are trying to get traffic by any means necessary.  I went back and looked at my expired listing on Etsy to make sure I had put "Cobblestone Quilting" on the picture and, sure enough I had but this person had cropped it out!!!  There was a place on their Flickr to send an email to them, which I have done.  There is also a place to report use of a personal photo by another person, which I did.   I guess from now on I will have to put a big watermark right across the center of my pictures.  Here is my original picture of the ornament sitting on my mom's crocheted doily. As you can see, it is pretty unique in relation to the fabric and you can clearly see the doily it is sitting on.  You can also see the Cobblestone Quilting at the bottom, which had been cropped out by the person who used it on her Flickr.