2. Cyber-bullying is a Relatable Issue
Basically the whole storyline around 'A' is largely associated with cyberbullying, which is a massive issue for many young women in a time which social media plays a huge part in our lives. The fact that 'A' also texts them on their phones at any given time show that Spencer, Emily, Hanna and Aria can't ever get away from their stalker and enemy. This is very true to how victims of cyberbullying in real life feel as well.