When it comes to photos on the Web, there are two kinds of sharing: letting others only view your pics, and letting others repost, remix, or otherwise have their way with them. Google+ makes it so you can easily share pictures through Creative Commons licensing, which gives you control over how they may be used by others, if at all. Here's how to do it:
- From Google+ (or any other Google site), select "Photos" from the top bar to bring up Picasa.
- Over in the top right corner, click the Options icon (it looks like a gear), and pick "Photos Settings."
- Select "Privacy and Permissions," then "Allow reuse with attribution" next to "Creative Commons."
- You may select further options, including letting others use your work for commercial gain, or the "Share-Alike" option, which lets others use your work for any purpose as long as they use a CC license for the resulting work.
- Click "Save changes" and you're all set!