By CBC News

Several popular Facebook applications have been sending users' personal information to advertising and internet tracking companies, the Wall Street Journal reported.

The newspaper said Monday that the breach includes users who set all their information to be completely private. In some cases, the apps provided access to names of friends.

A Facebook spokesman told the Journal on Sunday that the company would introduce new technology to contain the breach. It's not clear how long the breach went on.

The paper says Facebook also has taken immediate action to disable all applications that violated their terms.

Read more.

Are you concerned about your online privacy? Is using social network sites like Facebook worth risking your personal information?

(This is not a scientific survey. It is based on our readers' responses.)