That all depends on how you interpret the 4th Amendment and the Patriot Act. The 4th Amendment only protects against unreasonable search and seizures. In most cases, the government still has to get warrants (which require probable cause) or subpoenas to get information.
Basically, there is a thing called a "sneak 'n peek" They can come into your property and look without a search warrant. Now, this is only used for people they dub as very dangerous, such as people affiliated with terrorist organizations, and foreign countries, like sleeper agents or spys. But doesnt mean they dont use it on people that are not in those categories.