In a classroom off a small alley in eastern Paris, a fiery-haired teenager - who goes by the name of Clad Strife - lectures passionately about such things as the building of a Trojan horse.
It's not the deceptive vehicle of Greek legend he's describing, however, but a software tool for sneaking into computer systems.
The curriculum in this new school, called Zi Hackademy, is raising eyebrows in the French capital. While the academy's organizers say they're just trying to help people defend themselves by learning the tricks of the hacker's trade, some authorities and computer experts wonder if the lessons will end up promoting illegal cyberactivity.
The police have placed the school under surveillance. Michelle Bruno, a police spokesperson, says detectives are trying to determine whether teaching about hacking - as opposed to hacking itself - is illegal.
Since opening its graffiti-splattered doors last month, Zi Hackademy has attracted 36 people from around France - a motley group, including a grandmother, a French Microsoft executive. and a police officer from the provinces. Many say they are here because they want to improve their online skills and feel safer on the Internet.
"I don't want to crack any CIA or FBI codes or anything else which is illegal," says a director of a large start-up, who declines to give his name for publication. "This is just a hobby."
Clad Strife is also publicity-shy; he does not want to give his off-line name or age.
Before the day's lesson begins, the teacher explains his goal. "I'm going to reveal how I hacked into the website of a large Swiss company yesterday," says Strife, whose "day job" is attending high school."It took me just two minutes to access the hard disk," he says.
"If I show exactly how easy it was, the students will understand how to protect themselves and make sure it never happens to their own website."
But cyberexperts worry that some of the students, once they graduate, will not be able to resist the temptation of hacking.
Damien Bancal, the author of "Hackers and Pirates on the Internet," says that although he is sympathetic with the school's goal of cyber-self-defense, he has warned of the potential dangers of giving out the how-to's of hacking.
"If you tell kids how to make a Trojan Horse - software that enables them to take control of another computer - then they are going to be tempted to use it," he told a French newspaper.
Olivier Spinelli, the school's founder, describes himself as an idealist trying to provide a public service.
"The shadows only engender monsters," Mr. Spinelli says. "Life must be more transparent."
The academy's philosophy is that only if you become a hacker can you understand how hackers think and operate. The teachers stress that they are the Internet's good guys - or "white hats" - who look for lapses in security and alert others to problems so that they can be fixed. They say they have nothing in common with the "black hats" - virusmongers who crash systems and commit computer fraud.
Not everyone agrees with the "if you can't beat 'em, join 'em" approach.
Eric Barbry, a French lawyer specializing in the Internet, says hacking is illegal, no matter what the intent.
"Black hats and white hats both enter systems, which is unauthorized," he said. "It's the same as if I would enter your home, even if you left your door open. I might just be checking if there are no thieves, but I'm still trespassing. So what hackers do once they're inside is irrelevant."
The school's biggest problem, however, may be its close association with a magazine called "Hackerz Voice," published by Spinelli, who has said that hackers are "searching for the truth. After all, Socrates was a social hacker."
One recent edition explained how to invent a false credit card number for Internet shopping. Another article told readers how to illegally modify your mobile-phone settings in order to call at cheaper rates.
The most recent issue featured a "scoop" by one of the school's teachers called Fozzy, who disclosed how he was able to read the emails of 1.5 million French Internet users.
Publishing such information may soon become illegal. This week, the European Commission is set to pass tougher legislation on cybercrime, which is expected to become law by the end of the year.
Commission Spokesman Per Haugaard, when told about the Paris school for hackers, said: "If a school teaches you how to rob a bank, that's illegal, too. Whatever these hackers' romantic intentions, they still create an atmosphere of insecurity and make people wary of the Internet. That's the worst thing about it."
But for now, classes seem to be thriving at the school, where the decor includes a black flag with a grinning skull sporting an eyepatch (a nod to the French term for hackers, les cyber pirates). Courses are being taught at three levels: "Newbie" for beginners, "Wild" for the intermediate, and "Intrusion" for the "elite." A nine-hour lesson costs 450 French francs (about $60), payable in advance.
Still, for all their high-tech knowledge, these computer whiz kids seem to be able to offer only one payment that is hacker proof.
"If you want to pay by credit card, it's better to call us and tell us the number over the phone," the school's website advises. "This site is not safe."