Stop private data on your Mac from being sent to the Internet
Here's a helpful program that lets you see which applications are trying to send data out to the Internet. You can configure it to block applications from being able to send any data, or allow just the ones you trust to do so.
Read more: Stop private data on your Mac from being sent to the Internet
Story added 19. April 2012, content source with full text you can find at link above.