If I was looking to hack a corporation I would thank my friends for the suggestion. Or if I knew one of the people in the list of email address and was attracted to them, I could now move forward with my advances. OR if you pissed me off, I can start a smear campaign. COOL!
Why do I have these great addresses, you ask? Because you sent them to me. Don't you remember? You sent me a joke email or a cause email or a band announcement? And you left the email addresses visible! Thank you!
But you didn't have to. You could have hidden these address by performing once simple change...ADD the ADDY to the BCC! When you open a new email you will see the To line and below that you will see the CC and below that is the BCC. Let's discuss the difference.
To: this is the line where you add an email address or two depending on the group you are sending too. Like co-workers or bandmates.
CC: this is the line you use to add an email address to include someone. If you want someone to see the message, but it is aimed at the address in the To line.
BCC: this line is always hidden. If you want to send an email to a larger group but respect the privacy of the recipeients.
I had made this mistake in the past and have taken measures to keep that from happening again. Protect your friends, protect their email addresses! Going forward, ADD the ADDY to the BCC!