WEF attendees included Microsoft's Bill Gates, Yahoo's Tim Koogle, and public figures such as UN secretary general Kofi Annan and Palestinian leader Yasser Arafat. Some 1,400 credit card details were accessed.
This electronic security breach contrasts sharply to the impenetrability of the Davos conference centre, which was protected by roadblocks and barbed wire barricades to ward off anti-capitalist protesters.
Using Compaq Ipaq pocket PCs, which had been given to all the delegates at the conference, hackers were able to break into a "remnant database" and obtain 80,000 pages of information including passport information, personal cell phone contacts and Web site passwords.
Compaq, which last week boasted about its "superior technology services", was unable to comment on the breach because of a criminal investigation underway by the WEF. "While this investigation is underway and until we have a clearer understanding of what has happened and the probable cause, it is inappropriate to comment further," said a Compaq spokesman.