You're right, nobody and I mean nobody, who posts on the internet, is anonymous.
I remember vividly that day that I tragically lost all my guns in that tragic boating accident on Lake Michigan. They will have to do some serious diving to find them.
A national gun registration list in 2012-13 is not needed. Data-mining will reveal who owns what, unless you never used a credit card to purchase an ammo mag, rifle sight, case of ammo, etc.
They don’t need you to fill out a registration form saying you own an AR or AK. They will know in two seconds, by your credit card history.