It's a nice feeling when people like your work. They want to share it, show it off, tell the world, but somethimes thats really irritating, even if the person ment well.
Since 30 July 1998 the photographer owns full copyright in their images, even if they were commissioned by a third party; so if a photographer tells you as a model want they expect, gives instructions or asks you not to do something, then you do as you're told. I understand, having worked both behind and in front of the camera the process, but unfortunantly when you are working for a fine art photographer, you have no claim over the photos that are being taken. The photographer doesnt actually have to acknowledge you AT ALL.
I am usually quite happy to exchange time for print, but even then, my models have to understand that I need to know where my images are going, and for what use, before its okay to do so. Every photographer works differently, so a model needs to check before they do anything with any images they recieve. As my models agree for me to use the images commercially, it decreases the value of my images if a model uploads them everywhere, especially on facebook, twitter, myspace and tumblr. To some extent, I want to be able to help my models by getting more work, but trying to explain that they don't own the images, and therefore it is not cool to upload them all can be very fruastrating, especially when I'm working on photographs for a gallery exhibition. People dont want to buy works they've seen as your profile pic.
So keep this in mind, next time you're working with a fine art photographer- they dont have to ackowledge you as a model, but if they do, you know your work was spectacular, so maybe return the favour by respecting their wishes and instructions.