> Facebook can build a simple API which, given an email, tells you the trust rating of that person. That's, in general, a really good idea. Trouble is; it is s

> Facebook can build a simple API which, given an email, tells you the trust rating of that person. That's, in general, a really good idea. Trouble is; it is something that Google could trivially offer as well (in fact, they have even more metric data to work with). And the bigger problem is that you'd need to introduce it as a global standard so that email servers and clients would recognize it. > Emails from facebook can include the trust rating too. Sadly, that's easily spoofed :) The problem of trust online is the fundamental "flaw" in the internet (and the reason spam can exist in such a massive form). The person that solves this in a manageable and global way will be printing money.