Who's watching you online? Cyber stalkers are using increasingly sophisticated means to target their victims. In some cases, they are deploying spyware to get remote access to their quarry's computer - to access files and personal information. They might even be able to turn on the webcam to secretly film their victim.
5 live Investigates talks to senior police officers who say they need tougher powers to be able to investigate cyber stalking more effectively.
The programme hears from the victims of online stalking who've endured years of harassment and hate.
To contact the programme, tweet @5LInvestigates.