I grew up hiding in the bathroom to read - sharing a bedroom with my sister, it was my only quiet space.
In my last house, we had a large stack of magazines in my half-bath - the main bathroom had a few as well.
In our current house, I don't leave books in there (mostly because there's not a place to put them) but I do always take my phone/nook/ipad/etc. in there with me. The room is clean, I'm a 'sit while I flush' sort of girl (thanks to my mom and sister, the germaphobes, we were told to stay seated while it flushes to keep the germs in), so if I left something in there, I wouldn't be concerned.