This allowed the filmmakers to use on-set lighting to heighten the creepiness. Boyd, too, claimed that the episode played on the "inherent creepiness" of CCTV footage. Adam Kotsko has compared the modern conception of creepiness to the Freudian concept of "unheimlich". The episode received positive reviews, praising the creepiness of the villain. It has been described as "full of color, creepiness and unforgettable imagery". The album dealt with the nature of celebrity and "the creepiness of fandom as pathology". Another characteristic of creepiness is unpredictable behaviour. The letter's creepiness proved to be a local sensation. The depth and creepiness was also praised by Ken Tucker of "Entertainment Weekly". Several studies have hypothesized that creepiness is an evolutionary response to potentially dangerous situations. During the 20th century, association was made between involuntary celibacy and creepiness. There's a creepiness, as if someone's always watching you. Creepiness can be caused by the appearance of an individual. The concept of creepiness has only recently been formally addressed in social media marketing.