ACLU staff attorney Vasudha Talla explains:

"TSA is searching the electronic devices of domestic passengers, but without offering any reason for the search. We don't know why the government is singling out some passengers, and we don't know what exactly TSA is searching on the devices. Our phones and laptops contain very personal information, and the federal government should not be digging through our digital data without a warrant."

The rights and liberties watchdog wants to see the TSA's records detailing its policies, procedures or protocols when it comes to searching domestic passengers' devices. It also wants to see the equipment the TSA uses to probe deep into people's phones and laptops when they don't think manual searches are enough. Finally, it wants to know what kind of training the officers who conduct electronic searches get.

The question now is whether the TSA would comply with the ACLU's request -- this is the second FOIA the non-profit org filed following its first attempt in December 2017. ACLU says the "TSA has subsequently improperly withheld the requested records" that time, so it's putting the pressure on the agency to be more transparent yet again.

While the TSA is keeping procedures for domestic screening a secret, it did reveal that "border officials can search [international passengers'] devices with or without probable cause." The ACLU is also challenging that practice for international flights, especially since the agency's number of searches has ballooned considerably these past couple of years.