@joker>"It's weird that deleted photos still stay in the database. Wonder if eventually they will be overwritten..."
It's not really weird and no they won't be overwritten, although I bet they eat an enormous amount of server space. They are kept for a number of reasons, the *main* one being that the upload system has an algorithm that checks the *entire* database, including all previously uploaded pics, whether active or 'removed,' to ensure that the same pics aren't uploaded again. Supposedly, when it works right! But I've gotten error messages like, "This picture already uploaded," as well as, "This picture previously uploaded, removed for [whatever... AC, NFS, PQ, UA]."
It'd be way cool if it worked consistently, but it's really hit-or-miss, maybe *half* the time it finds a duplicate, half the time not, such as when I've uploaded an *exact* duplicate with multiple girls in it from one of their galleries to another. Does that make sense now?
Another reason might involve legality, so he has proof of what was uploaded or removed, and by whom (copyrighted, etc.)