Renee Kelleher has memorised the mugshot displayed on her computer screen. Listed beneath the man's photograph are his crimes -- two counts of lewd or lascivious acts upon a child -- and his address, only a couple of blocks from the Tampa, Florida, home of Renee, her husband, James, and their 3-year-old daughter, Francis. About once a month, Kelleher clicks on the Web site of the state Department of Law Enforcement and scrolls through the list of sex offenders in her postcode. She's not alone. Around 20,000 people monthly visit Florida's online sexual predator and offender registry. While the Internet has developed a reputation as a bastion for sexual predators, paedophiles and pornographers, law enforcement agencies are trying to make it a tool to combat them. Fifteen states, numerous counties and cities, and several freelance individuals have posted the identities and whereabouts of sex offenders on the Internet. Four more states have recently passed bills to enact online sex offender registries. It is part of a national push in the US to notify the public about registered sex offenders. And millions of parents have visited such sites, relying on the logic: If you know who the sex offenders in your area are, you will be better equipped to protect your family from them. Law enforcement agencies running such Web sites say the registries arm parents with a powerful tool -- information -- and parents are grateful. "Overall, reactions have been very positive," says Mary Coffee, at Florida's Sex Offender and Predator Unit. "There has not been a single negative call from a parent that I know of. People are really surprised and appreciative to have this information available to them. The only negative responses have been from the offenders themselves." But online registries are not without their critics. Some say they can cause more damage than they prevent by accidentally revealing the names of victims, creating instant mailing lists for child pornographers and subjecting people who have completed their time in prison to further punishment. "It's a political solution that looks good but likely does more harm than good because it undermines the stability of offenders," says Deborah Jacobs, executive director of the American Civil Liberties Union of Eastern Missouri. There are no plans to put the UK's sex offenders registry online, according to a Home Office spokesman. Currently, the registry is held only by the police force in the area a known paedophile lives and it is left to their discretion how much information to disclose to the public. "In extreme cases the police may decide to notify the public. It depends on their risk assessment," the spokesman said. He believes the vigilante threat posed by releasing information about paedophiles to the general public would outweigh the benefits. David Kerr, chief executive of the Internet Watch Foundation (IWF) agrees that putting the sex offenders' registry on the Net raises problems. "We would have concerns about the balance between protecting kids and the right to individual freedom," he said. ACPO (Association of Chief Police Officers) spokesman on child protection Chief Constable Tony Butler believes publishing sex offenders whereabouts on the Net would be a retrograde step. "We are trying to manage sex offenders in the community. To publish on the Internet would cause unnecessary fear and alarm in the community," he said.