As stated in the US Bill of Rights: "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."
The security of individuals and organizations (other than governments in some cases) in themselves and their property, including their homes and vehicles and storage and other property, whether owned or rented, tangible or intangible, and the contents thereof, and their non-aggressive activities, and their confidential records and discussions with anyone pertaining to any of the above, must not be violated except by a valid warrant issued by a valid court. This requires genuine probable cause based on an honest belief (based on actual evidence) that the individual or organization concerned is likely to have committed a specific crime and the property or information to be searched for or seized is evidence of that crime. Any property seized or confidential information disclosed must be evidence of the specified crime and must be returned to its rightful owner after the case is finished. Confidential information must not be revealed or used other than as needed for the case. Other property or information discovered in the search cannot be seized or used even if it's evidence of another crime, without first applying for and obtaining a valid warrant for that other property or information on that basis. Property cannot be taken or damaged just to inconvenience the owner. A warrant cannot be obtained just to look around for evidence in general; it must be for specific evidence honestly believed to exist. Allegations of "terrorism" or appeals to "national security" are not valid excuses to get a warrant, without evidence of an actual specific crime.
In addition, a person's or organization's confidential discussions with any kind of advisor or counsel (including but not limited to spiritual, moral, ethical, psychological, medical, legal, business, and financial advice, and consultations with a spouse or family member or business associate) may not be violated without a warrant as above, and to apply for the warrant also requires compelling evidence that either the advisor is not merely acting as counsel but is actually conspiring with the person or organization to commit a crime, or that the person or organization has informed the advisor of intent to commit a crime despite the advisor's warning that the usual professional confidentiality cannot apply in that case.
A warrant can also be obtained to look for evidence or information that could exonerate someone. In that case, anything found may be used to exonerate anyone as applicable, whether it was named on the search or not. Nothing found in such a search may be used to incriminate anyone.
If these rules are not followed, or it is determined that a search or seizure was invalid or illegal (including by planting or tampering with evidence) or otherwise affected by government misconduct, then nothing discovered directly or indirectly thereby may be used to incriminate anyone; it may be used only to exonerate.