I let a friend of a friend to sleep on my couch and I later found out that without my knowledge he had kept marijuana in his suitcase while he was staying here. This got me thinking, what if a bag of marijuana had fallen out and been left under my couch? There would be no way to prove I knew it was there, but also no way for me to prove that I didnt. Or waaaay worse, what if he had left a cd full of child pornography on my coffee table? I know this is hypothethical but its been driving me crazy to think how vulnerable I might have been!