VANCOUVER - The Vancouver Winter Olympics are less than 100 days away but they're already getting visitors, not necessarily welcome ones.

Computer systems that are the Games' public face have been probed for vulnerabilities, a Games official responsible for technology security says.

Barry Caswell, director of information technology operations for the Vancouver Organizing Committee (VANOC), stops short of characterizing these as cyber attacks.

"The answer to that would be no,'' he says. "We do see some level of scanning across some of our online presence. It tends to be people knocking at the door and just checking it out and looking.

"So we've monitored and watched that closely but we've had no attacks worthy of mention.''

Some people are just curious, says Caswell, who makes it seem largely benign, something big businesses and government agencies experience all the time.

But it's the virtual equivalent of someone walking past a row of parked cars, trying door handles.

"This is, let's call it, technically savvy and aware people that are scanning the systems and wanting to do some basic understanding, maybe with a question: Are they (the networks) vulnerable to something in particular?'' says Caswell.

"Typically it's automated and there's no one sort of behind the scenes. It's machines working and scanning and looking for vulnerabilities to generally plant some kind of code if they have that possibility.''

The Games' networks handle things ranging from managing logistics such as accommodation and accreditation for athletes, officials, volunteers and media, to access to venues and event timing and scoring.

They're also responsible for distribution of results and feeds to TV networks and other media, not to mention internal systems for employees, VANOC finance and communication.

VANOC also has links to commercial sponsors, Olympic partners and government agencies connected with the Games.

The RCMP-led Integrated Security Team won't talk about specific plans to protect critical computer networks, saying only that they have ``policies and mechanisms in place to monitor and evaluate potential risks.''

Cyber-security expert Howard Schmidt says Olympics are tempting targets for everyone from criminals looking to exploit Games interest for gain to people with a grudge - so-called ``hacktivists.''

Protecting those systems while allowing the expected high volume of legitimate data traffic they'll generate is a major challenge, he says.

"You have to do the capacity planning not only for the peak but also the peak, plus whatever attack might take place,'' says Schmidt, president of the Information Security Forum, a London-based organization whose members include private companies and governments.

"You also have to have effectively a SWAT team, if you would, of cyber-security teams and your IT professionals to identify what anomalies are,'' says Schmidt, who as a federal agent worked on the 2002 Salt Lake Winter Olympics, as well as the 2000 Sydney and 1996 Atlanta Summer Games.

"We never know when another vulnerability's going to be discovered.''

No one wanted to talk about details of cyber attacks at previous Games, including the most recent in Beijing last year.

Schmidt says at Salt Lake, officials faced old-school hacking attempts and distributed denial-of-service attacks, where armies of compromised computers flood networks with information requests to make them unusable.

"There was a fair amount,'' he recalls. "The good news was a lot of it was shunted because there was planning ahead.''

Police followed the intruders' electronic trails but Schmidt admits they weren't very successful at catching them. The tools today are better.

"That was a lifetime ago from a technology perspective,'' he says, adding the law is also beginning to catch up and allow police to chase cyber criminals across jurisdictional borders.

Though it didn't target Salt Lake Games networks, American servers did come under attack after U.S. speed skater Apolo Ohno won a gold medal in a controversial race that saw his South Korean rival disqualified.

Investigators said the source of the attack appeared to be South Korea.

"We didn't see really any political or state but we did see the `hacktivist' group,'' says Schmidt. "You look at world events and there's always somebody angry about something.''

Cyber attacks are attractive because they're fairly low risk, he says.

"You've got all those things that get people's passions flared. Now, instead of having to be there, you can sit at a computer and in some cases generate that through services that are provided by other criminals.''

Schmidt and current Games security officials also expect a surge in purely criminal activities such as phishing, where bogus web sites or emails pretending to have Olympic content will tempt users to click and expose their computers to attack.

For that, says Caswell, there's little VANOC can do but educate people about where to find legitimate Games portals.

In Beijing, police busted a counterfeit Games ticketing scam that used an official-looking web site.

"That probably is a lesson learned,'' says Simon Edgett director of Olympic architecture at Bell Canada, VANOC's telecom partner.

However well Games networks are hardened, Schmidt warns that other critical systems not directly connected to the Olympics also need scrutiny.

For instance, travel for athletes, officials and visitors could be thrown into chaos simply by hacking into airlines' electronic-ticketing systems and messing with reservations.

"It's the collateral areas you need to worry about,'' says Schmidt.