What does the "exclusionary rule" protect against?

The exclusionary rule is a legal principle that protects individuals from the use of evidence obtained through violations of their Fourth Amendment rights, specifically regarding illegal searches and seizures. This rule ensures that any evidence obtained in a manner that infringes upon a person's constitutional rights cannot be used in court. This protection is essential for maintaining the integrity of the legal process and upholding citizens' rights against governmental overreach.

In contrast, other answers do not align with the direct purpose of the exclusionary rule. Hearsay evidence pertains to the admissibility of testimony rather than how evidence is collected. Testimony given under duress involves concerns about the voluntariness and reliability of witness statements, while the presumption of innocence is a fundamental principle of criminal law that ensures defendants are regarded as innocent until proven guilty, but it does not relate specifically to how evidence is obtained. Thus, the most relevant and accurate answer to the question is that the exclusionary rule protects against illegal search and seizure.