Well...

It's because ACLU’s case rests on whether the law violates the Fourth Amendment, which protects citizens against "unreasonable searches" by the government.

So why is the the authorities able to force trucking companies to drug test and maintain detailed records of its drivers if it's an unreasonable search? I mean, the guy's just doing his job, isn't he? Why isn't the ACLU all up in arms about that?