Let's say, that I (Gary) am a member of Facebook. When I log on Facebook offers to search through my e-mail contact list to find other friends that may be on Facebook. So I give it permission to upload my Gmail contacts list and search through for friends to find those who are also on Facebook.
I did not give it permission though to actually contact everybody in my Gmail list and invite them. That is what is happening here I assume? It's one thing to find those who are already on Facebook and make the connection... but it is a serious invasion of privacy to e-mail all of my contacts and invite them without my permission.... and to hold on to that e-mail list for future marketing purposes. I did not give FB permission to do that, and neither did the owners of each e-mail address in my contact list.
Facebook cannot however import my contact list or any of my contacts lists without my or their permission.