A headline can be a scary thing.
Take this one: "Warrantless car searches OK'd."
Warrantless searches strike an unpleasant and even fearful chord in most people, expecially those who are familiar with the Constitution's Fourth Amendment: "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."
Earlier this week the Pennsylvania Supreme Court clarified that in the Keystone State, police may search a vehicle without a warrant if they have probable cause to do so.
What? You mean a policeman can just pull a driver over willy-nilly and ferret through their car?
No. They have to be able to convince a judge that they had probable cause to do it.
For instance, if a driver is speeding or driving erratically, and pulled over on that basis, and when the driver's window is rolled down, the officer is treated to the distinctive aroma of a Grateful Dead concert, there would be probable cause to look for the source. If, in the course of that search, a large quantity of herbs of a controlled nature, along with other things like loaded weapons are found, the officer would be permitted to bring charges based on those things and present them as evidence at trial.
Remember, the Fourth Amendment uses the word "unreasonable." It is the only amendment that actually states the concept of reason and practicality, which should be inherent in all law.
The First Amendment, that collection of commandments which enumerate unalienable rights that the government cannot usurp, should also be viewed in the context of reason and practicality. We have rights to free speech, religion, assembly and press, but none of those supplant the concept of reason. We have freedom of speech, but not to scream "fire" in a crowded theater. We have freedom of religion, but not to perform dangerous rituals. We can assemble, but not riot. We have a press that is not immune to prosecution for libel or slander.
The assumption has to be that police will be reasonable, and if they are not, the matter will be ultimately remedied by a court, the ultimate legal authority.