Where the privacy interests of the owner are weakened (like in a pervasively regulated business such as liquor, guns, mining, and junkyards), and the government interests in regulating particular businesses are concomitantly heightened, a warrantless inspection of commercial premises may well be reasonable within the meaning of the Fourth Amendment. For a search to be reasonable, the regulatory statute must perform the two basic functions of a warrant: it must advise the owner of the commercial premises that the search is being made pursuant to the law and has a properly defined scope, and it must limit the discretion of the inspecting officers. To perform this first function, the statute must be “sufficiently comprehensive and defined that the owner of commercial property cannot help but be aware that his property will be subject to periodic inspections undertaken for specific purposes.” In addition, in defining how a statute limits the discretion of the inspectors, we have observed that it must be “carefully limited in time, place, and scope.”