Probable Cause & Consent
The law is if you consent then police can search or ask questions, anytime or anywhere. The problem is the word "consent". Statistics show that an overwhelming majority of people do not feel free to leave, to tell an officer to get lost when law enforcement approach them and ask questions. They feel compelled to consent to questioning and a search. [See Tracy Maclin, "Black and Blue Encounters -- Some Preliminary Thoughts About Fourth Amendment Seizures: Should Race Matter?" Valparaiso University Law Review 26 (1991): 249-50.]
The United States Supreme Court has held that it does not matter what the accused felt, whether he felt free to leave or if he felt like he was seized, but instead what a reasonable person would believe. [Florida v Bostick, 501 U.S. 429, 441 (1991)]. However, the Supreme Court has acknowledged that if one's right to refuse consent were truly "knowing, intelligent, and voluntary", it would "in practice create serious doubt whether consent searches would continue to be conducted.” [Schneckloth v Bustamonte, 412 U.S. 218, 229 (1973)]. Law enforcement needs individuals to consent otherwise they would lose out on a large amount of their convictions. However, the majority of people do not dare to tell law enforcement, No!