I recently needed to contact an ebay seller with a photo, illustrating a problem with an item I purchased. When I uploaded the photo this popup appeared, and I really liked the plain language letting me know other people might be looking at it. This serves both to give me a chance to censor any photo that might show private things like me, my kids, home, etc. – and also as a general reminder to people that the internet isn’t private and we need to be mindful.
I wish there were more little notes like these when we post stuff in places we assume to be private.