Not only because there is somebody that steals the scans.
Nowaways I became friend of some doujinkas... and they don't like it, and, I respect it.
So, if somebody added me to friendlist only for the scans, you can erase me, you're wasting your time here.
I'm not going to delete the old scans, I'll make them private.
Be sure I won't scan again (just if a friend wants, but I'll not share it public).