Problems with Email Forwarding

we all forward emails now and then. But seldom we realize that we are also sending email addresses of our pals which may be misused. the person to whom you are forwarding may not do something with that email addresses, but there is a possibility that it might reach a hand which will misuse it. I have seen it being misused by some students on my campus. what r ur thoughts on this!
According to me all major email providers should provide an option asking whether you want to obfuscate the email addresses present in forwarded email message. This is quite easy but none of the major email providers paid attention to it.
I have now started working on developing a plug in for a squirrelmail email client which will provide this feature if that plugin is installed.