Todd
I have a problem with him giving up Dave's dad. There was no point of volunteering the information to Chris unless he was trying to get back at Dave.
As a result of his stupidity, someone paid the ultimate price.
Also, Todd is never shown to have felt any remorse over his actions.
The "internet" heroes that showed up for the climatic battle would have attacked Todd because they would have seen him as the enemy. For Todd to easily switch sides is dumb and lazy script writing.