What do I do?

Ok let me start by saying my MIL is like crazy sensitive and lonely. She sits in the house all day and out of 5 kids only 2 visit her regularly and her husband is always gone. My son is 2 weeks old and he sees her alot. I know she's excited to have her first grandson and he is her only sons only child but she is driving me nuts posting so many pictures of him to Facebook. I don't mind family taking a few pics and posting one or two but she has uploaded so many pictures of him since birth, some of which I didn't know she took and all of them posted without my permission... like she posted a pic of me breastfeeding him after birth and posted it to fb! I'm so sick of everytime we come over she has a million pictures posted of him like she's his damn mom! Let the truth be told I really didn't even want a lot of pics of him on fb at all for many reasons. To make it worst, 2 of his sisters keeps taking them too and sending them to her, one of which will take him from my arms, even when he is sleeping, and get some pics. I don't want to be stingy with the baby but he's MY fucking son! They'll feel like I'm being possessive if I say no more pics and nobody can hold him anymore but it's only been 2 weeks and I've had it! What do I do?