Cyberstalking threat to many, says Plaid MP Elfyn Llwyd
An urgent review and reform of stalking laws is the aim of a parliamentary inquiry into harassment, which started on Thursday.
The MPs will also examine the effect of social media on "cyberstalking".
Plaid Cymru MP Elfyn Llwyd, who leads the inquiry, said social media and new technology offered the means to anonymously target people.
He said cyberstalking was not covered by UK law, but a threat to "potentially millions of vulnerable people".
The first session will also cover the work of the National Stalking Helpline.
Mr Llwyd, chair of the justice unions group, said the cross-party inquiry was the first independent examination of the issues in the UK.
Interviewees will include academics, a psychologist and representatives from the Suzy Lamplugh Trust and the National Stalking Helpline.
Written evidence will also be accepted from police, probation staff, magistrates, judges and stalking victims.
It is hoped a parliamentary bill will be compiled in 2012.
Mr Llwyd said: "In 2010, 53,000 incidents of stalking and harassment were recorded by the police in the UK - just 2.2% of these cases resulted in a custodial sentence.
"While it is not clear yet whether cyberstalking is a growing trend in isolation or just one more way in which to stalk someone, it is a worrying development.
"We are surrounded by new technologies and social media - and unfortunately this is a way in which people can be anonymously targeted.
"Cyberstalking is a very real threat to potentially millions of vulnerable people. Crucially - it is not covered by UK law.
'Lessen the threat'
"This is one of the reasons why the 1997 Protection from Harassment Act needs to be urgently reviewed."
He added: "We'll hear more about the nature of cyberstalking in our first evidence session and we'll also hear from charities and operators of the National Stalking Helpline.
"Listening to the experts will help us to begin forming the case for where we go from here.
"Together with reviewing the substantive law, we'll look at changing sentencing practices and guidelines.
"As part of the final recommendations, the group consider what treatment programmes need to be available for perpetrators so as to lessen the threat of re-offending.
"We will also look at developing training for the police and the Probation Service to help them deal effectively with victims and perpetrators of stalking."
Laura Richards, from the Protection Against Stalking (PAS) charity, said: "This is about homicide prevention.
"Too often PAS hears from and supports victims who have been continually let down and rendered further vulnerable by the criminal justice system.
"This must change. Recent high profile murder cases show how dangerous stalking is. Not only do stalkers steal lives - they take lives."