I have the same problem. I've been on and off collecting porn movies or pictures from different sites. Sometimes i would grow sick of them and deleted all of my movies and photos (except the ones on dvd's) but in my moments of sorrow i would go back into collecting them. I don't even see the whole movie or the picture gallery, i just put them on my favourites and that's it. When i have hundreds of favourites like that i realise i have a problem and i reconsider my position in life.
I rarely use facebook cause it's so vast, once you signed in it takes a least an hour to go trough the latest changes in your friends profiles. I only keep it in case i need to find someone. My girlfriend (of almost six years now) has a problem with facebook. She is going trough profiles and imagines everyone's happy and starting a family with kids, and she is not and get's really depressed. She knows my problem but cannot help me at this time. I guess in a way i let in my addiction because i'm not satisfied with my actual sex life and like to escape in my fantasies. I hope i will get over it someday and i'm inspired of what i read on this forum.