According to the rules, your board does have to be labeled "Share Your Memories". Upload your pics to it. Then share the URL with the contest website by the deadline.
This tells me the pictures have to be yours only and cannot contain anyone in the pic (that is recognizable) that you don't have permission from. That to me means that if there are people in the background that you can't really make out their faces, you wouldn't need their permission. Just the "recognizable" ones.
Also no branding. So you can't take a picture of your family in front of the new Starbucks sign and submit, for example.
Since the work has to be your own, I don't think you could use a photopass photo either.
It seems simple really. Take your pictures, upload, enter.