* Law enforcement will claim (possibly lie) that a person is a child predator in order to get cooperation from neighbors/etc. Who wouldn't want to help get a child predator off the streets? If you don't assist, maybe you're a child predator yourself!
* Law enforcement can plant child pornography with relative ease. Maybe a polaroid tossed into your back yard or left on your trash can outside. Or maybe an image with CSS display:none injected into some webpage you visit (which may sit in your cache for some time).
Normally I would consider these to be conspiracy theories.
But when we start seeing stories like this, I have to wonder if there is any manipulation here.
We the people respond pretty intensely to any accusations of sexual abuse of a child. Our knee-jerk reaction is "get the noose ready!", so we're pretty open to manipulation.
Maybe this guy is guilty as hell...but this is a ridiculous precedent to set. What happens if someone sustains a cranial injury that affects their memory?