[[quoteright:350:http://static.tvtropes.org/pmwiki/pub/images/falling_down_nightmare_fuel.jpg]]
* The story Foster tells to the family after he crashes their barbecue, that ends with him and his family "all sleeping together in the dark", [[spoiler: which seems to imply that Foster intends to [[PaterFamilicide kill his wife, his daughter, and himself]] once he gets to them.]] The dreamy way he tells the story just makes it worse, as he genuinely seems to feel ''that is the right thing to do''.
* Foster's constant phone calls to his wife, which progressively become more chilling and threatening with each one. She calls the police over to her house twice, and both times they leave quickly, determining Foster to be a non-threat, and give her the mere advice to keep her doors locked in case. Foster's final phone call provokes Beth to pick up her daughter and leave the house from out the back when she realizes that he's calling her from ''right down the block''.
* The whole movie becomes this once you get to the end, in part due to ParanoiaFuel. Given that many people find Foster [[JerkassWoobie sympathetic]], it makes one wonder just how easily this could actually happen to them or someone they know.
** Really just [[FromNobodyToNightmare Foster himself]]. Basically, he's a guy who had a really [[SanitySlippage bad day]]. An [[RidiculouslyAverageGuy average joe]], the white collar working man, a simple human being who feels [[CorneredRattleSnake pushed into a corner]] [[RageBreakingPoint and is]] [[DisproportionateRetribution lashing out in various]], brutal, over the top ways as possible. And, do you want to know [[FromBadToWorse the real scary part]]? ... [[TruthInTelevision There are people]] [[ParanoiaFuel just like him]].
* The Whammy Burger scene can be this for some, considering that this could happen to ''[[ParanoiaFuel anyone]]''.
* The Neo-Nazi freak whose favorite possessions are an anti-tank weapon and a used can of Zyklon-B.
* The Latino gangbangers try to kill Foster in a drive-by shooting. They miss Foster, but do hit several other people by accident. Imagine being one of the innocent bystanders who got shot, out of the blue, without knowing why.