Most folks, took the little amount of time it takes, to actually give credit or attribution.
Recently though, I found the below picture from my riding in Europe, on a Facebook side for B.A.D.D., it showed up as liked on my news feed by a friend on FB.
Note: the one on the page in question was before I added the watermark you see.
So, as usual, I went to the page and added replies that included a link to the original posting, on the comments on that facebook page posting when folks asked where the picture was taken.
I then messaged the admin and asked that in the future he place an attribution link.
The admin replied, saying because of all the members of his "group", they didn't do that. He also mentioned because I wasn't a member, my comments with links to the posting would be "faded out". I asked him what that meant, and he said that as I was not a member of the page, the comments would only be visible to me and my friends. Oh, but if I made a contribution to the site, then he'd post my pictures.
I dithered on this for days, finally donated the minimum amount: $1. The admin messaged me with "Fuck off with your dollar" and "stop wasting his time".
Nice huh. I wished I'd kept that FB conversation so I could post it here, but I was pretty angry at the time.
So, I was in the process of looking up how to report theft of intellectual property on Facebook and found he'd taken down my picture from the b.a.d.d page.
That's good enough for me, probably should have done that in the first place.
So, watermarks from now on.