From United States v. Jones:

MR. DREEBEN: Well, this Court held in Whren v. United States that when the police have probable cause to stop someone for a traffic violation they can do that. There are protections –

JUSTICE GINSBURG: That was when the police came upon the violator. But this is, it’s all in the computer. The police can say, we want to find out more about X, so consult the database, see if there is an indication that he was ever speeding in the last 28 days.