Good for you. No one should be able to upload to your showcase only you should have control and mods. But don't feel bad there are folks that use 5yrs and older photos still. Many use photos from other source.
Have to say I have seen some very funny showcases over the years. As a Photographer and one that has worked with many models of various shapes and sizes, I do get a kick out of some of the showcases.
But it all good in fun. Many get disappointed though who venture on the showcase alone. Glad there are many that have the complete package: Personality, attitude, enjoyment, humor and much more.