This has been making the rounds in the blogosphere these past few days: Vonage is taking months/years old addresses, submitted ONLY for a forward-to-a-friend promotion, and sending advertising to those people years later.
If true, it violates all best practice guidelines for appropriate email marketing.
If true, it's questionably legal.
The worst/best part is that the emails Vonage sent claim to be new referrals, saying "Andy Sernowitz asked us to tell you..." even though Andy Sernowitz apparently hasn't asked Vonage to do this in many, many months.
Psst, Vonage? Ever heard of Jumpstart? If not, I suspect you will be learning more about that particular FTC action soon enough.