People are being urged to be wary of the information they post on social networking sites to reduce the risk of becoming a victim of cyber-stalking.
Devon and Cornwall Police said stalking was a key factor in many domestic abuse cases and was predominantly committed by a former partner after a relationship has ended.
According to the British Crime Survey, one in five women and one in 10 men report being stalked at some point in their lives with instances increasing with the growth of internet use and the popularity of social networking sites such as Facebook and Twitter.
Elizabeth, a victim from Devon, was cyber-stalked by a previously abusive partner who found information and her whereabouts many years later and stalked her on line.
"It was very easy for my stalker to track my movements and harass me through Facebook and similar social media sites.," she said. "He would go to terrifying lengths to find out my whereabouts.
"He was able to add information about me that was untrue to my social networks. These sites operate with minimal security so it is crucial to find the appropriate privacy settings to keep safe on line."
Cyber-stalking can involve harassment through the internet, email, social networking sites or text messages.
Key advice includes checking privacy policies on social networking sites and adjusting settings to protect your privacy.
Police also warned users to be careful not to disclose personal information, such as your home address, date of birth and phone number.
Steven Slater, computer forensic manager for Devon and Cornwall Police, said: "It is important to remind people to be cautious with the information they choose to add on line and to check their privacy settings.
"People should not post anything they would not be happy for other people to see. Even if information was originally private it could become public at a later stage."
Former ITV Westcountry anchor Alexis Bowater became a high-profile victim of stalking when she and a female colleague were sent more than 50 emails of a violent and sexual nature.
Now chief executive of Stalking UK, she said: "Social networking sites are a great way to keep in touch with friends and family but the information added, however inconsequential, can be used by an ex-partner for cyber-stalking.
"Cyber-stalking and stalking are misunderstood crimes and we know people still don't recognise stalking behaviour when it's happening to them. Even though they may feel uncomfortable with someone's obsessive behaviour all too often people put up with it."