Reasonable suspicion is based on experience and opinion that a criminal activity has occurred, is occurring, or is likely to occur. Probable cause is based on facts and circumstances that are sufficient to justify a belief that a criminal act has been or is being committed.

Exceptions to the Warrant Requirement. There are seven warrant exceptions:

arrest
consent
vehicle
stop and frisk
plain view
emergency situations
borders and airports.
Exceptions explained:

-When the police arrest the person. The police must have a warrant or a reasonable suspicion that the person has committed a crime. They can search the person and the area within his immediate control as part of a lawful arrest.
-When the person voluntarily agrees to the search. The person must voluntarily grant permission for the search – it’s not consent if the person is forced or coerced to agree.
-When the police have probable cause to believe that a vehicle contains contraband. Police can search vehicles without warrants because the vehicle and the evidence might get away while police are waiting for the warrant. They must have probable cause to stop and search the vehicle, though.
-When the police officer reasonably thinks a person is behaving suspiciously and is likely to be armed. The officer may stop that person and frisk for weapons to protect officer safety. This is called a Terry stop and it is based on the famous Supreme Court case of Terry v. Ohio.
-When an object connected with a crime is in plain view and can be seen from a place where the officer is allowed to be. For example, if an officer stops a car for a traffic violation and sees a gun lying on the seat next to the driver, the officer may seize it.
-When the police encounter certain emergency situations where people are in danger and the police do not have time to get a warrant, they may enter and/or search the building to protect people’s safety. Examples include searching a building after a telephoned bomb threat, or entering a house that appears to be on fire.
-Government officials may search people and their belongings at borders and airports. In light of the danger posed, the government has placed restrictions on air travel and entering the country. By entering the secure area at an airport or a border checkpoint, people have agreed to accept a certain amount of government intrusion into their privacy.

Sylvia is at the airport, in a hurry to catch her flight. after checking her luggage, she goes to the security checkpoint, puts her bag through the machine and walks through the metal detector. at the gate, when she goes to board the plane, the tsa officials pull her aside and say they need randomly view the information on her ipad.
a. is the warranties search legal?
b. if it's legal, list and explain which of the 7 exception rules applies.