Final answer:
The plain view exception enables police to seize items without a warrant if they're in plain sight and the officers are lawfully present. Probable cause is necessary for warrantless searches, but the Fourth Amendment generally requires a search warrant for searches and seizures.
Step-by-step explanation:
The plain view exception to the warrant requirement allows police to seize contraband without a warrant when it is in plain sight, they are lawfully in the location from where the item can be seen, and it is immediately apparent that the item is contraband or evidence of a crime. This concept operates under the legal standard of probable cause, which permits law enforcement to conduct searches or seizures based on a reasonable belief that a crime has been committed, which is a lower standard than the proof required for a conviction. However, in general, the Fourth Amendment protects individuals from unreasonable searches and seizures by requiring a search warrant issued by a judge on probable cause, except in certain circumstances such as consent by the owner, exigent circumstances, warrant errors believed in good faith, or inevitable discovery of evidence.