Watermarks- make 'em loud and proud! So many times in this digital era we have our images "stolen" or used without permission. In my opinion this is wrong on all accounts, but if we don't do something to protect ourselves I truly believewe are asking for it. I know we shouldn't "have to" do it, but we need to stop being naive in our belief that just because people shouldn't that they won't.
People will always steal, and I'd dare those reading this to be honest with themselves and ask if they've ever downloaded a song they haven't paid for. Personally I've never downloaded a song or movie that I didn't pay for, but back in the old days I did make mix tapes by sharing friends' cassette tapes with each other.
Solution 1. Make a good sized banner on the bottom of your image so everyone can know where the image came from. Sometimes people are just excited to show your image, so it's important that you give yourself credit because more often than not, they won't.
Solution 2: Put your name in three or more areas across your image diagonally so it crosses many different areas of your shot. I do it at 25% opacity. This means any user will not be able to crop it in Facebook without your name appearing. They'd have to take it into Photoshop and clone it out which is time consuming. On top of that the images that I post on FB are so low res that their attempts to edit them will not succeed, there's just not enough data there to do it.
In summary, stop whining about people using or taking your shots without your permission and do something about it. Be proactive rather than reactive. If you've done all I mention above and they still do it, go to war with them. Because at that point they've shown that they are willing to do whatever it takes to steal your shot.
Until next time, I hope this helps!