I think there is something in the Bill of Rights that has something about this
4th Amendment to the US Constitution
"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."
As for the concept of welfare having the government try to "help" people I believe it is very inefficient and if people truly wanted to help the poor then they would push for charities to take care of the poor. A majority of the money that is allocated for welfare goes to the bureaucrats that administer the program (I have seen people say 70% and up) and not to the people that it is "supposed to help".