When I talk at local high schools about online safety I warn teens that any photo you put online is essentially there forever because of caches, archives, and the possibility of others copying it or even archiving it. They get very anxious and one invariably pops up and says "but I can delete them!" Ah, if it were only that easy. You can certainly stop it being visible at a certain point, but deleted? Really removed from the entire Internet? Not so much.

Anyway, even if there's only so much you can do to attempt to make the undesired photos vanish from the online world, it's still worth not just leaving them around, is it?

Turns out that there are two ways to delete images from Google Plus depending on how they've been uploaded. I'll show you both, you can then easily figure out which will apply to the images you have on your G+ account.

In my own Photos area, I noticed that I have an image that somehow ended up duplicated:

When I click on the image, I can see more details on exactly how I shared it when I uploaded the one that I now want to delete:

Given this, one way to force it to be deleted from Google Plus is to simply unshare it. How to do that? Click on "Public" on the top left and it'll show you the original share options:

Now click on the "x" on the green "Public" button and now there's no-one with whom you've shared this picture:

Click on "Save" and Google Plus is smart enough to recognize that the photo is orphaned...

Click on "Stop sharing" and *poof* that image vanishes from the site.

The other possibility when you click on a photo on G+ is that it gives you the option to edit the photo. With a toolbar like this:

Don't click on "Edit", just click on the trashcan icon and...

There ya go. Either way, you can see how to proceed with cleaning up your photo collection on Google Plus!