When do you talk to your kids - predetors

[Antony]

I don't watch much TV but I've just seen a most disturbing show on people (men) who prey upon young children (boys and girls).

I have a great family, one 9 year old girl, and one 6 year old boy, and their mother, my terrific wife of 12 years.

Of course we are computer literate, and my children go on-line to play games based on each of their teachers' reccomendations.

After seeing the way some people act, I'm now wondering when is the time to talk to my children about these types of activities?

Darn, no "real" problems with my family unit, it just scared me to see all of these men "out there" looking for young children.

When do you suggest the dialog begin? At what age is this sort of topic not just 'scary' for our children? When does this dialog 'need' to begin?

Any serious adivice will be much appreciated.