Like "Exactly. Common sense should be your guide. Anything you post in a message is public, anything that's behind the password is not. Aside from google and others indexing pages and analyzing keywords to make sure the searches are correct there are many other things out there to comb sites and pull info off for less than legal or dubiously legal things. Eg harvesting email addresses to put on lists to sell to spammers. Use common sense and you'll be fine. There is plenty more information people can find out about you via public records (SSN, credit record, driving record, address, how much you paid for your house, birth record, where you work, how much you earn, how often you pay taxes, how much tax you pay, police record plus many others) that posts online is not really any worse."