The key is to post only low res images so they can see, but not likely pilfer high res. Online can make a 72dpi image look decent, but if you try to take that 72dpi image and enlarge it for printing, it looks like crap. If I'm posting online I re-size the image smaller, drop the dpi to 72, and save the new file as a reference file copy by adding an "a" to the end of the file number. Thus, _DSC1191.jpg, becomes _DSC1191a.jpg and they stand side by side in your original folder. It's easy enough for you to remember which is the high res, and which is the low res. And if you'll message me your home address, I still owe you $15 for the high res image you sent me at Christmas. You do some nice work and I apologize for suspecting that "SC" was not the same person as "xgen70," but I too value intellectual and creative property rights, and you're entitled to yours.
I can fully empathize with your concern about others using your images without permission or compensation. Not long after I posted this image that I took of Drex Harrington

imagine my surprise when I saw it being used to solicit advertisers for Swell Info by none other than Micah, and I never got so much as a "Would you mind if I used this?" If he had asked, I probably would have said yes and been flattered, but there's something flat out wrong about not even asking. I sent him a note and have heard nothing in return, and that shot was taken in 2007 during Hurricane Noel. Copyright laws matter, in spite of, and maybe even because of, the internet.