It probably depends on where the pictures are hosted. For example, if you have AT&T internet service, and you host the pictures on an AT&T site that was provided with your service, other AT&T users may be able to see the pictures, but those using a rival service provider may not be able to. It's best to host pictures on a generic host, such as one of the photo hosting providers like PhotoBucket or the Ga Fiero host. I'm still trying to figure out an easy way for folks to upload pics to this host.