[paulojreis]

> "Make this "opt-in"" is a statement, not a procedure. How, and why?

I don't really care about the procedure; Snailmail, if need be. Convenience is not a valid argument for breaking privacy.

> Would the cons outwheigh the pros?

The answer to this is dependent on one's stance. As you may imagine, from where I stand, they do (clearly). I can't see any "logistical inconvenience" justify breaking privacy by default.