4. Identity Leakage

Hannah's digital intruder has left a trail of data in the menacing messages, that could be clues to their identity. It's time to call in the experts.

stalked@bbc.co.uk

Hosts: Carole Cadwalladr and Hannah Mossman Moore. Producers: Rob Byrne and Georgia Catt Original music and vocals by Self Esteem Original music: Phil Channell Sound design by Phil Channel, Rob Byrne and Georgia Catt Actor: Zak Shukor Series editor: Philip Sellars Commissioner: Dylan Haskins

Linguistic Analysis: Robert Leonard, Marlon Hurt, Juliane Ford, Dakota Wing, Rachel S Audrey T, Zara R, Amanda I.

Original footage from: BurchDurch / YouTube Stalked is a BBC Studios Audio production for BBC Sounds and Radio 5live

Episodes released every Tuesday