Breech of patient's confidentiality

I'm a professor for Nursing and allied health courses. Just recently I was put in an Operating Room area handling 6 students at a time. As a clinical intructor, I have informed students about house rules etc. esp the use of cellphone and digital cameras. So, for them not to use their cellphones, I told then that I will be using mine and just post it on fb. By doin this, nurses from other hospitals got violent reactions of me posting those pictures, the chief nurse even called the hospital where I am having my duty to ask me to delete those pictures. As for me, I feel disgraced on the thought that I don't have a clear understanding of that law. Btw, the pictures that I posted are pictures of my students assisting the surgeries, patient's name, face, body parts esp. private parts are covered.