Concordia University has blocked its campus computers from accessing Facebook because of online security concerns.

The Montreal university's desktop network is vulnerable to hackers who may be using the popular social networking site to access personal information, according to the school's information technology department. The school is concerned that the information could then be used to launch attacks on its systems.

"We are increasingly becoming targets of spamming, phishing expeditions, etc.," said Chris Mota, director of media relations at Concordia. "They're becoming extremely sophisticated."

Social networking sites such as Facebook may be part of the problem because users upload personal information, including e-mail addresses.

Last week dozens of people received fraudulent e-mails purported to be from the IT department requesting user names and passwords as part of an effort to upgrade the school's web accounts. About 70 people responded, Mota said.

Blocking desktop access to Facebook is a first step, and other social networking sites are being evaluated.

Facebook is still available on campus through wireless connections, which are readily accessible from individual students' and professors' laptop computers.

The site is becoming an important tool for academic research, university recreational activities and alumni campaigns, Mota said.

More than 60,000 people regularly use Concordia's desktop computer system.