The Fourth Amendment outlines legal protocols on how information can be collected. It states that no unreasonable search and seizure is permitted. This means that the police force cannot search a vehicle without “probable cause” (having some sort of testimony or incriminating evidence) unless a warrant was previously signed by a judge. However, an exception to these rules is if a violation is in “plain sight” (e.g. packets of marijuana in the open), where police can take immediate action. These rules ensure that defendants have a fair chance to explain themselves and prepare if likely to be questioned.