Harry Potter and the Half-Blood Prince, the sixth book in the series, is due out at 12:01 am on Saturday, and the odds are that a career online scammer is working on a legitimate-looking email pitch offering the opportunity to buy the book online.

This possibility has prompted a warning from secure messaging vendor Mirapoint for Potter fans to beware. "Even opening an email like that is troublesome," said Bethany Mayer, chief marketing officer at Mirapoint. "And many of these [email messages] look legitimate."

Mirapoint and The Radicati Group, a consulting and marketing research firm that focuses on the messaging space, conducted a survey of about 800 internet users and found that 11 percent of respondents buy products and services pitched to them by spam email, resulting in more than 9 percent losing money.

"They take advantage of whatever large event puts people in need," Mayer said. "In some cases it's a fun event like Harry Potter."

In other cases, it's an event like Hurricane Dennis, which struck the US northern Gulf Coast early this week, and could well prompt bogus relief solicitations. "Spammers don't seem to discriminate," Mayer said.

More than 1.4 million copies of the US and UK editions of the book have been ordered at Amazon.com. At 4:05pm on Tuesday, when Amazon.com put out a press release with the figures, more than 870,000 copies had been ordered from its US website, topping the previous record, set by Harry Potter and the Order of the Phoenix, the fifth book in the series.

The internet is rife with “leaks” about the sixth book's plot and the possibility of deaths in the story. Author JK Rowling has issued a statement on her official website, www.jkrowling.com, warning that such rumours are easy to spread and advising fans to "keep those barrels of salt handy".

She's also apparently not terribly keen on the misuse of her good name on internet postings at fan sites. She never posts on fan sites and certainly wouldn't publish her email address that way, Rowling writes on her site.

"Love you all though I do, I don't really want to wake up tomorrow and have to download 21,956,038 new emails, all demanding the identity of the Half-Blood Prince," her message says.

Well, perhaps not all of them would make that demand. Some might be offers to sell her the book online.