News reports this morning are linking an e-mail warning with actual hijackings that have taken place in Johannesburg. 

According to news on 94.7 Higheld Stereo, an e-mail is "doing the rounds" which warns visitors to Melrose Arch that hijackers are following  victims home from the precinct and then hijacking them at home.
The e-mail is being tenuously linked to two hijackings where victims dined at Melrose Arch and were later hijacked at their homes.
The reports raise the profile of unsolicited mail (or spam) but also raise a question about whether these kind of warnings – whether they are founded in fact or not – can help people become more aware and prevent them from becoming victims of crime.
There can't be many PC users who haven't received mass-mail warnings about security risks that are more or less feasible. On the whole, these belong to the group of mail known as spam and most companies discourage their dissemination.
Brett Myroff, CEO of security distributor NetXactics, says the Melrose Arch mail has been doing the rounds for a while now.
"Because we do not know if this is indeed happening from Melrose Arch we cannot say if the e-mails are valid or not, and therefore cannot say if people should heed this specific warning," he says.
"I think, due to the unfortunate fact that crime in our country is unacceptably high, people should always be vigilant, not only in specific unsubstantiated scenarios."
Because South Africans are very aware and nervous of the crime problem we are facing, stories like this will always invoke emotion and people will spread the e-mails, he adds.
"We do not advocate unsolicited e-mails and, since these claims to the best of my knowledge are unsubstantiated, we would tend to view them as spam.
"However, any action that could prevent people becoming victims of crime gets our support 100% – although we have to be careful of scaremongering."
Myroff suggests that a crime advisory service from the SA Police Services would solve the dilemma by providing an official, substantiated channel for this type of communication.