"I have noticed when I report a picture/page Facebook identifies me to the individual/group I reported. This seems as a built in technique to discourage people to report. I have been harassed afterwards and while I can block individuals I cannot block pages. Maybe this is something we can take up with FB (perhaps you already are)." - comment from woman on stoprapebook
Update: Just got another message about this:
"Hi! I just started following your page and have this far reported several extraordinarily offensive images. I was shocked this morning to find a very hurtful and offensive response from one of the pages in my inbox (I sent generic 'there's something about this that offends me, please take it down. And got back 'there's something about my penis. Please put it in your mouth.' Until now I really don't think I fully comprehended how horrible the world has gotten. I considered responding to the poster, but decided to transform into something positive: Thank you for being courageous in taking on this very important work. I bet you will encounter hatred and resistance, but stay strong and know your work is so very needed."