I have to agree with Beatrice...
The new tools are not the answer to the fact that people log on to sl anonymously and then, after they're caught for causing problems, log in again as someone else...ad infinitum.
It seems to me that the new no-info sign up is not increasing population as much as it's increasing the number of people who are signing up with multiple accounts.
I can't believe that it's too costly or too difficult to require SOME sort of identifying asset - credit card, online bank account, offline bank account - anything! I have frequently considered upgrading to a premium account, but have continued to hesitate because of all the problems with protecting land.
Listen to your users, Lindens...You have a gold mine and a great environment. Don't let it collapse under its own weight. Make use of the preview environment, protect the adult users from underage users and those who would destroy the environment, and require some proof of age and responsibility.