This amendment prohibits unreasonable searches and seizures. It also requires probable cause for searches and arrests and requires a judge to sign arrest warrants. Simplified, it means that if a person is stopped to be searched, an officer must have a good excuse – a good reason for thinking that a search is necessary. That is what “probable cause” means.
The pros: suspected drunk drivers can be stopped and prevented from killing someone; suspicious-acting people boarding airplanes can be stopped to prevent terrorism; kids bringing weapons to school can be searched to have the weapon removed, saving lives – your locker can even be searched in school if there is probable cause; a person’s locker or backpack can be searched if there is reason to suspect you have a weapon or drugs; fleeing criminals can be apprehended if a police officer spots a car speeding or driving erratically; cars can be inspected during an Amber Alert if there is suspicion that an abducted child may be inside.
Cons: overzealous law enforcement agents may search people without the proper “probable cause”; people might be racially profiled unnecessarily if they look like a terrorist or an illegal alien; some people believe searches are an invasion of privacy; some people have been unnecessarily injured, roughed up and even killed during searches, even when there is “probable cause”; in the state where I live, a man was killed because the police barged into his home looking for crack (they had probable cause), but they had the wrong address, so an innocent man was killed.