Three men were jailed recently for plotting to rape two young sisters. The BBC reported that it was the first time that internet chat logs had been used to prove a charge of conspiracy to rape a child. Detective Constable Dave Adams told the BBC: "This case should act as a really stark warning that the internet is not a hiding place to plan and participate in criminal acts." He's right: a pub would better suit their ends because the conversation is unlikely to be recorded.

The intentions of David Beavan, Alan Hedgcock and Robert Myers only came to light because Beavan changed his mind and ratted on the other two. Had Beavan not walked into Bournemouth police station, a terrible crime may have followed. DC Adams's comments implied that the internet played some part in the detection and prevention of a terrible act. It didn't. It just made it easy to prove the intent of Beaven and the two men he named.

Meanwhile, Home Secretary John Reid said he may make paedophiles list their online identities on the Sex Offenders Register as part of his effort to "protect our children". Unlike moving house, a username or email address can be changed in about two minutes, so, again, it's difficult to see how this can make a real difference to detection and prevention of a crime.

Reid proposed that mechanisms would flag up anyone using a blacklisted identity on popular web sites used by kids. His plans risk giving misplaced comfort to parents who worry about their own children's use of the internet. There are established mechanisms for keeping kids out of web sites that prohibit under-18s, like credit card checks. These mechanisms are not infallible but it is far more difficult to keep adults out of sites for kids. That's a more important message for Reid to convey to parents.