This book was pretty okay. Maybe I was expecting a little bit more, I'm not sure, but while I did enjoy it, I wasn't totally overjoyed with it. 
I loved the idea behind the book, we all love a good vigilante killer, especially one that defends young girls being targeted. but it fell flat for me throughout most of the story. I found the characters to be somewhat cliche and typical for a college campus setting. Naive, shy and quiet girl befriends nerdy guy and loud, beautiful and confident roommate. Been there, done that, a thousand and one times. 
I enjoyed Scarletts parts more than Carly's for that reason and because I love a strong female protagonist/anti hero, and that's more so what I got with Scarlett. That being said, I was disappointed that we didn't dive deeper into her psyche. We did kind of scratch the surface a few times talking about urges and craving the thrill, but we didn't go much deeper than that, and I felt as though I needed more depth to her character in order to really connect with her.
Other than Drew, and possibly Mina, (it's hard to say because we got so little of her character) every single other person that showed up in this book had zero redeeming qualities and I very strongly disliked (bordering hate) all of them and that made it hard for me to want to keep picking up this book. I just didn't look forward to it.
It was pretty easy to guess the “twist” both at the one third mark, and at the end of the story and I was disappointed not to be surprised by either reveal, even if I did appreciate them. 

It was a good book, not great but overall, I did enjoy it.