Fourth Amendment for reference: The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures,

Fourth Amendment for reference: The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized. According to the text of this amendment, it looks like it does not apply to what you're describing. The 4th amendment protects citizens from having their governments unreasonably search their property or take it from them. The thing to notice here is the word, unreasonably. Information volunteered is not considered to be an unreasonable search (Example: You're pulled over and the officer, without cause, attempts to search your car. Unless they have a probable cause they must ask permission. If something is in plain site it is fair game though.) I don't understand what you mean that everything will be public information. If you're referring to information we voluntarily distribute to companies such as Google and Myspace, it falls under whatever agreement you consented to when you joined their service. That information is still considered private and protected, which is why the authorities must obtain a court order (via: probable cause) to get the information from the service provider.