Eh. I feel the positives outweigh the negatives. Sure, we could hole up in a cave and only give pseudonyms, but the information is still out there. Heck, a newspaper article on my family revealed their full names, birthdate, city, and even my wife's name, birthdate and year. Easier even still to track us from the mall (people know us now) or to raid our mailbox or such.
I feel absolute security (or even anything remotely secure) is just an illusion. Take all the waiting and security checks at airports, or even putting deadbolts on front doors. If someone really wanted to do something, those measures wouldn't be enough. All I guess we can prevent is the casual crook - make them work a bit to trackdown the info or break into your house.
So I pick a middle ground - share what I want without being too blatant about it.