SEOUL, South Korea —  More than 220,000 South Koreans have been victims of online identity theft in connection with a popular Web-based fantasy game, a sign of growing problems with information protection in one of the world's most wired countries.

The victims have filed complaints with the operator of "Lineage" in the past week after discovering that accounts for the game had been set up in their names without their knowledge, the Seoul-based game company NCSoft said.

To sign up for a game account, Internet users must provide their name and resident registration number, which is the main form of national identification. Police are investigating who stole the personal information.

Although there have been no reports of any financial losses, the case has raised concern that such leaked personal information could be used for more serious crimes.

South Korean firms have been criticized for demanding too much personal information from customers for online transactions while not protecting them properly.

Now this scandal has awakened South Korea — with the highest per-capita rate of broadband connections in the world — to the need for better information security.

"Lineage" is based around the story of a prince and five knights fighting to regain a lost throne. As players progress through the game, they can win special abilities, called "items," which can be sold to other online players.