A bipartisan pair of U.S. senators on Tuesday pressed the leaders of AT&T and data storage company Snowflake for more information about the scope of a recent breach that allowed cybercriminals to steal records on “nearly all” of the phone giant’s customers.

“There is no reason to believe that AT&T’s sensitive data will not also be auctioned and fall into the hands of criminals and foreign intelligence agencies,” Sens. Richard Blumenthal (D-CT) and Josh Hawley (R-MO), the leaders of the Judiciary Committee’s privacy subpanel, wrote Tuesday in a letter to AT&T Chief Executive Officer John Stankey.

The duo also sent a missive to Snowflake CEO Sridhar Ramaswamy that said the theft of AT&T subscriber information “appears to be connected with an ongoing series of breaches” of the company’s clients, including Ticketmaster, Advance Auto Parts, and Santander Bank.

“Disturbingly, the Ticketmaster and AT&T breaches appears [sic] to have been easily preventable,” they wrote to Ramaswamy.

Blumenthal and Hawley gave the corporate leaders until July 29 to answer a series of questions about the breach, which stretched over a six-month period, including: how the hackers behind the AT&T break-in gained access to Snowflake services; what kind of probe, if any, Snowflake has conducted into the incident; and what notifications either company sent to clients whose accounts were hacked.