I was scared out of my wits just a few days ago when I walking back home and saw a smiley face on the ground. It was yellow, but it was exactly like the ones Red John makes. I was just like O.O -"Holy crap. Run!" XD
The sad/cool/creepy part of it is, you're absolutely right. every time i now see a smiley face i can't help but imagine the blood. But, then again, my career of choice is cutting up dead people to find evidence for the police, so my brain may be a bit on the dramatic side.