I was recently forced to purge hundreds of photos from my Flickr account, as they changed ownership and subsequently changed their free model. It made me realize the impermanence of anything online - everything is bound to the terms-of-service, and the reality is that all this representation of thoughts and feelings are nothing more than ones and zeroes in a hard drive somewhere, waiting for the plug to get pulled.
Not that the idiosyncrasies of half-thought drivel are of importance to anyone, but I wonder if it bodes the same for our memories. That one day, everything will be forgotten.