When an anonymous person or persons eats a noticable amount of the snacks in your house; and nobody fesses up when parents/siblings get pissed off and the issue is adressed. A great excuse to get your family off your ass.
Sister: Where the hell did all of the oreos go?
Me: i dont know.
Mom: Bullshit, you're the one who had friends over last night! I just bought those oreos yesterday morning!
Me: Looks to me like some paranormal snacktivity..