You might think that the end of the world would bring out the best in those few who survive but as Valve reminds us with some vaguely sad yet very funny scribblings on a Crash Course safe house wall, not even the walking dead can save us from anonymous trolls.
You have to give credit to Valve for knowing its audience and for having a pretty good insight into the human psyche, too. It's nice to think that people are generally good-hearted and compassionate toward one another, and that when the chips are down they'll pull together to triumph over adversity and all that good stuff. The latter is often true but it's obvious that the guys behind Left 4 Dead aren't completely convinced about the former.
Case in point: Graffiti on the wall of a safe house in the Crash Course DLC. On it, a woman named Alison has written a heartfelt poem to Jonathan, a fellow survivor (and probable lover) who has fallen in the flight from the undead. "You taught all that knew you what courage meant and have shown us an example in death as you did in life," she wrote. "God give me strength in my life without you and I shall thank him. I can only hope our souls shall entwine again in that place where there is only love." Not great, perhaps, but certainly a touching memorial to one who was loved and lost.
But sometime between Alison's departure and your arrival, the internet showed up and plastered the wall with other, less pleasant (but infinitely more amusing) messages. Directly underneath her signature, for example, is the message, "PS IM FAT." Other pearls of wisdom include, "Roses are Red, Violents are Blue, You Suck," "QQ," and my personal favorite, "Jesus, lady, I'm hiding from zombies and reading this was the most terrible thing to happen to me today."
Not that this is the first time the internet has intruded upon the apocalypse: As Shamus Young pointed out, no matter where you go, human nature will follow. Who would've thought that in the midst of a zombie holocaust, you'd have to watch out for trolls, too?