FYI an informative blog post by +Mike Spinak.
Here's what the result can be when images are re-uploaded without permission:
Self-Proclaimed Photo Montage Virtuoso Is Sued for Stealing Photos
http://pdnpulse.com/2012/08/self-proclaimed-photo-montage-virtuoso-is-sued-for-stealing-photos.html
Don't confuse re-uploading with using a site's "Share" function. Using a site's built-in Share function should be fine, since the site's Terms and Conditions tend to obtain permission from the uploading photographers for use of the photo while delivering the site's service.
Reshared post from +Mike Spinak
Today's blog post is packed with information photographers need to know.
If you're new to my blog, I invite you to circle me and read along as I share.
If you like this, please re-share the links, and help me bring my pictures and writing to a wider audience.
Thank you.
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Fighting Back Against Online Copyright Violators
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Comments
What about tagging the curator in the post?
Thanks +Jeff Sullivan and +Mike Spinak for the posts. As a curator for +ScienceSunday we have discussed this among the SciSun curators. Even on a re-share, we try to find the source for pictures. There was a picture of lightening striking a volcano that made it to "what's hot" with our hashtag. There was nothing else. I did an image search to see if it was Photoshopped or where it was taken etc. It turned out to be a winning photo in a contest for news photographers. I alerted the OP before re-sharing it via our Page. He did nothing.
Our goal is to promote science and share our passion for science. We've noticed that if you just post text about a topic, you might get a few pluses However, if you search for a related image to add, the image draws people in and they stay for the science. One of the issues is that the re-share option (take 500px.com as an example) has, is that the thumbnail is not enough to draw people in. Personally I've avoided re-sharing some great work due to copyright concerns, even though we are not doing this for profit by any stretch of the imagination. We thought we understood "fair use" but we were directed to another infringement case that made us more cautious.
Love the subtext message in the image you chose for this!
Eyo!