m.orkut.com , the mobile version of Orkut displays email id of all your friends in your orkut profile (and vice versa) . Initially I thought this was a security vulnerability, and orkut help says.
"Can I hide my primary email address on orkut from my friends?
Once you add another orkut user to your friends list, it's not possible to prevent them from seeing your primary email address"
Friends according to google include
- best friends
- good friends
- haven't met
This is very useful but very harmful...Suggest orkut to make primary id private here...
Update: Google posted about this feature just now...