Address harvesting through social networks

The next killer ap on the Internet seems to be social networking. Everyone has a great idea for the next facebook or or myspace. All of these sites, though, have to find users. The site will fail if there are no users. One way to get new users is to ask all your current users to invite all their friends to join. This tends to lead to the marketing / product decision to insert functionality into the social networking site which allows current users to upload their address book and the site itself will send out invitations to all your friends and contacts.
This is not actually as great as an idea as it sounds, however. First, you end up with situations like what happened to me this past week.  On Wednesday I received the following email:

Hi,
I looked for you on Reunion.com, the largest people search service — but you weren’t there.
See who else has been searching for you! Click here.
—Bob
Reunion.com – Life Changes. Keep in Touch.™
You have received this email because a Reunion.com Member sent an invitation to this email address. For assistance, please refer to our FAQ or Contact Us.
Our Address: 2118 Wilshire Blvd., Box 1008, Santa Monica, CA 90403-5784

Bob is actually a current client and I recognized his full name in the from address. Bob has my current information and we have had contact within the last few weeks so I know he is not actually using reunion.com to try and find me. I spend a few minutes poking at reunion.com trying to figure out how to make the mail stop and make sure they never bother me again, discover they do not want to make that easy and give up. I can always block them if their email becomes annoying.
The next day, I receive an email from Bob, it says:

All,
If you received an email from reunion.com on my behalf, please IGNORE it as that email was sent without my knowledge and I have not sent it willingly. This email was sent to all my contacts in my email address book.
I have already cancelled my account on that site and it is really weird that the site would do this without my permission.
The site is “force inviting” people from your contacts if you register on the site, which is very annoying.
Thanks,
—
Bob

Because of this behaviour, reunion.com has now lost one registered user, and he has told all his contacts to avoid the site in the future.
Reunion.com is not alone in their rush to grab any address they can get a hold of. Most sites will let you upload address books, or your account information so they can mail all your contacts introducing their new product. It is an attempt to appear to be organic viral marketing, but it is not. In point of fact it is no different than randomly harvesting addresses off websites and mailing them.
Social networks need to be very careful about appropriating addresses and assuming permission. This week, reunion.com appropriated both Bob’s address and my own and assumed they had permission to email me on Bob’s behalf. In fact, they did not have Bob’s permission to appropriate his address and they certainly did not have my permission to contact me.
Many newborn social networks are using similar types of spam to spread their presence. It remains to be seen if this is a working strategy or if they are forced to actually start actually caring about permission.