It's more an ethical question than anything else. Do you want to build your fortunes on the invasion of other people's privacies? Don't do to others what you don't want others to do to you.
Whether it's a buy now is whether you think Facebook will be the thing kids are using in ten years. (My nieces don't know what email is, only Facebook.)
Regardless of how Facebook.com does going forward, they have an incredible amount of talent working there. I think that's where the value is, so long as they can retain it and actually pump out some cool products.
