I would never in 5 million years take someone's mattress from the trash, but that is absolutely not out of the ordinary to see it done. Hell, when I was moving from Chicago, I was throwing out things like a kind of broken vaccuum and after my second trip to the garbage (I was placing them outside of the dumpster because I knew people would still want this stuff) this guy just stood there because he wanted me to just hand it to him so he could take it.