NETFLIX'S ‘terrifying’ new stalker drama You is so scary according to fans, they're having trouble sleeping.

Based on the book by Caroline Kepnes it follows bookshop manager Joe Goldberg, played by Gossip Girl's Penn Badgley, 32, who becomes obsessed with poetry student, Guinevere Beck, played by Elizabeth Lail, 26.

Since coming on Netflix on 26 December, the show has been binge-watched by viewers around the country.

Flocking to Twitter, fans have shared in their droves how 'terrifying' the series is. One wrote: "I just completed #YOU and I'm mentally disturbed like wtf just happened."

Another agreed tweeting: "Oh my god #YOU on @netflixUK is disturbing as f*** but I'm obsessed."

One viewer went a little further to analyse the show: "#YouOnNetflix is a terrifying example of how far a manic pixie obsession can really go. Also dunno how I feel about the creepy dude as the central character who has redeeming qualities? I guess maybe that's the point- that you never know who's a psycopath [sic]."

If you haven't watched the series or read the book, beware there are spoilers ahead.

The pilot episode begins as Joe watches Beck enter the bookshop where he works in Brooklyn, New York.

As she makes her way through the shelves we hear Joe say: "Well hello there. Who are you?"

As brooding Joe surveys Beck he makes several precise observations that we later discover to be startlingly accurate.

As we see Joe try and get closer to Beck, he goes to extreme lengths to win the affection of his obsession.

Starting with Beck's current hook-up, Benji, we watch as he works his way through her friends and family eliminating anyone who might prevent him from achieving his goal.

Although Joe's methods are creepy, illegal and often murderous, many viewers couldn't help but comment that they found him strangely attractive.

One of the creepiest aspects of the show is the ease in which Joe manages to discover so much about Beck. All through social media.

By working his way through her Instagram, Twitter and Facebook, Joe discovers where she goes to university, who her friends are and scarily, where she lives.

Writing on Twitter, obviously, fans couldn't help but express how this had left them feeling.

One fan wrote: "Ok I watched #YouOnNetflix in two days and dang I wanna delete my instagram now [sic]."

While another joked: "I thought women were supposed to be the stalkers on social media."

One fan commented: "Pretty dark, but considering the ability to find out everything about anyone on social media these days, it's worth a watch."