LEANDRA RAMM (pictured) is a mezzo-soprano with more on her mind than music. Someone—a deranged Singaporean cyber-stalker, she claims—has posted around 4,000 internet messages in the past five years, depicting her as a talentless, sex-crazed swindler. He has also created a blog under her name and has left obscene messages on her own website.

Ms Ramm, who lives in New York, has had scant help from the American police, who say the offence is committed in Singapore. But she says the police in Singapore have shown no interest. Ms Ramm says her career, social life and emotional well-being have all suffered. Not only does she get daily death threats, but so do all those associated with her: friends, family, colleagues and boss. She says she feels “humiliated, helpless and abused”.

Police and prosecutors say that cyber-stalking—the persistent use of the internet, e-mail, social networks, instant messaging or related digital devices to annoy, harass or threaten—is growing, and that they lack the legal tools to combat it.

A study by the Bureau of Justice Statistics in America estimates that cyber-stalking afflicted around a quarter of the 3.4m stalking victims it has tallied over the age of 18 in the United States in 2006. Mike Proctor, a detective based in California with over 20 years of experience in dealing with stalking cases, says that more and more include internet harassment. He describes the crime as “woefully underprosecuted”. Barack Obama highlighted the issue in a Presidential Proclamation in December to mark Stalking Awareness Month. “Increasingly, stalkers use modern technology to monitor and torment their victims, and one in four victims reports some form of cyber-stalking—such as threatening e-mails or instant messaging—as part of their harassment,” it said.

Rachel MacKenzie, a psychologist who runs a behaviour programme for stalkers in the Australian state of Victoria, says that many now harass their victims through the internet. For some stalkers, the internet is just a tool of the trade. Others deploy it exclusively. But the victims of both kinds of stalker may be as frightened as those threatened physically. “There is always the fear that the stalking will enter the real world,” she says. In Germany a senior detective specialising in cybercrime in Frankfurt am Main, Birgit Roth, says that internet harassment is present in some 40% of stalking cases that her force investigates. She says that victims are as traumatised as the survivors of a plane crash.

The misery they inflict seems to motivate cyber-stalkers. A pregnant victim says she barricades herself in her home and has “morbid thoughts” every day: whether her child will be born or grow up without one of its parents. Her stalker, an ex-colleague with a military background, harasses her through social-networking sites, threatening physical attack on her family.

As with many internet crimes, the law is struggling to keep up. As Ms Ramm's case demonstrates, many stalkers threaten their victims from abroad, often from countries without stalking laws. American-based internet service providers (ISPs) and firms such as Google, Yahoo! and Facebook, require court orders for information about stalkers to be served in the country of their headquarters. That can be costly and time-consuming.

Nazir Afzal, an expert on stalking at Britain's Crown Prosecution Service, says such requests can mean delays of up to three months. A real-world stalker can be arrested within hours. Mr Afzal adds that ISPs often delete e-mail data after 30 days. If the victim has also deleted the distressing e-mail, the evidence may be gone for good. Other ISPs insist on notifying their customers that the police are investigating.

Technical dodges give stalkers more flexibility. Special software allows them to send untraceable e-mails from concealed internet addresses. And investigators say that they are unable to monitor instant messaging. Valerie Caproni, General Counsel for the Federal Bureau of Investigation, complained to the House Judiciary Committee in February that her agency lacked powers to gather evidence on stalkers using peer-to-peer and social networks.

No wonder, then, that victims have little confidence in the criminal-justice system to protect them. Emma Short, a British psychologist who is setting up the world's first outfit dedicated to researching cyber-stalking, says that few victims think the police can help them and many do not report the crime. Nearly one-third say they suffered at least one symptom of post-traumatic stress disorder.

Alexis Bowater, the chief executive of a British charity, the Network for Surviving Stalking, is campaigning for European Union countries to adopt a common approach to stalking: only 12 out of 27 member states have specific laws against it. She wants others to follow Britain's lead. Police there assess every stalking case for the risk of violence; prosecutors have issued guidance on how to handle cases, and schemes are afoot to make perpetrators receive treatment when convicted. Mr Afzal is also seeking greater use of voluntary disclosure of information about suspected stalkers by agreement with mobile-phone companies and ISPs. This already happens with suspected child abusers.

Without cross-border progress on all these fronts, the deranged or vengeful will continue to enjoy virtual impunity. Ms Ramm says, “One day we will all look back, shocked that people were allowed to get away with stalking on the internet.”