I received an email from a Dutch friend, inviting me to view his photos. He's an artistic person, so I was eager to see what he wanted to share. It was on a site I didn't know about, Zoosk, which required that I create an account. I did so. Part of the sign-up was to enter my email login to see which of my friends are on the site. I did that, though now see that my guard was down.
After seeing that my friend had no photos shared and that the site was a dating site, I left.
Then, I started getting emails and calls from friends and colleagues. Zoosk had hijacked my email account to send everyone an email invitation from me to see my photos. It went through my contact list - every personal and business listing, and spammed them an invitation to see my photos on a dating site.
I called to complain and get a log of the messages it sent out through my email account, and was given the "I understand your frustration..." message. They said that if I'd read the signup very very carefully, I would have seen that it promised to do this evil deed.
If this is not outright illegal, it should be. It's deceptive, damaging, compromises privacy and security.