Answer to Question 1
The strong government interest in controlling who and what enters the United States is balanced against the significant reductions of individual Fourth Amendment rights at international borders. Routine detentions at international airports, seaports, and the Canadian and Mexican land borders do not require reasonable suspicion to back up lengthy detentions and frisks, including examining purses, wallets, pockets, and even up-close dog sniffs.
Answer to Question 2
An anonymous tip can provide reasonable suspicion. However, it will not automatically provide reasonable suspicion. In one case, Alabama v. White, police received an anonymous tip claiming that a person would leave a particular apartment carrying cocaine, get into a certain car, and drive to a certain location. If the police acted on the tip alone, this would not have justified a Terry stop. However, their observation corroborated the information given by the anonymous informer. Therefore, the police were justified in believing that the informant had inside information about the suspect and, thus, in crediting the informant's claim that the person in the apartment possessed cocaine.
However, in Florida v. J.L., the Court found that an anonymous tip that was corroborated did not provide reasonable suspicion. The tip in this case said that a young black man standing at a particular bus stop and wearing certain clothing was carrying a gun. Since this tip did not predict future activity that could be corroborated, it did not provide a reasonable enough basis for believing that the informant had knowledge of the criminal activity.