The CEOs of Apple and Alphabet received letters Monday from the Energy and Commerce Committee asking for answers about the collection of data through their devices and services, such as email, location data and voice.

The letters were signed by full Committee Chairman Greg Walden, Communications and Technology Subcommittee Chairman Marsha Blackburn, Oversight and Investigations Subcommittee Chairman Gregg Harper, and Digital Commerce and Consumer Protection Subcommittee Chairman Bob Latta.

The letters were specifically addressed to Apple CEO Tim Cook and Alphabet CEO Larry Page. Alphabet is Google’s parent company.

The letter to Cook focused on Siri and Apple’s operating system.

The letter to Page focused on Android and Google Assistant.

In both cases, media reports were used as fodder for the questions.

With regard to Google, one such report, published in November 2017, referenced that Android phones collect information on nearby cellular towers “even when location services, WiFi and Bluetooth capabilities are disabled, no third-party apps are installed or running, and the phones lack subscriber identification modules (SIM) cards.”

The letter also referenced reports that smartphone devices can collect non-triggered audio data from user conversations when the phone recognizes a “trigger” phrase, such as “okay Google.”

The passages in the letters were drawn from media reports from publications such as The Wall Street Journal and Quartz, and even Google’s and Apple’s own online documentation.

The letters ask the CEO to respond to the questions no later than July 23, 2018. For Page, the questions in the letter also included follow-up questions, mostly about the Android operating system and how it tracks data.

For example, one question asks: “When an Android phone lacks a SIM card, it that phone programmed to collect and locally store information through a different data collection capability, if available, regarding” either a nearby cellular tower, nearby WiFi hotspot or nearby Bluetooth beacon?

If the answer to any of those questions is “yes,” it then asks whether Android phones without SIM cards are “programmed to send this locally-stored information to Google when one or more networking capabilities are established.”