Six U.S. senators have reportedly asked Yahoo CEO Marissa Mayer to explain the 2-year-old massive data breach that happened under her tutelage.

On Tuesday, the Democratic U.S. senators issued a joint letter to Mayer asking her to provide more details about Yahoo’s investigation over the hack that occurred in 2014., Reuters reports. 

The lawmakers, who admitted that they were “disturbed” by the incident that only came to light last week, are compelling Mayer to lay down more facts about the data breach that affected 500 million user accounts. 

The senators pointed out in the letter that the breach may have compromised millions of Americans’ data for two years, adding that the hack that took place under Mayer’s wing is “unacceptable.”

The joint letter comes a day after Verizon-unit AOL CEO Tim Armstrong was asked if Verizon is in the process of renegotiating its deal to buy the core assets of Mayer’s company. "On both sides, the contract has very good protections ... on the sale process," Armstrong said. 

Armstrong also reportedly said that Verizon is working closely with Yahoo in investigating the data breach, noting that the process is “calmly” and “methodically” flowing, as per CNBC

Contrary to Armstrong's statement, however, the New York Post reported that Verizon executives are pondering on how the company should proceed with the $4.8 billion deal with Yahoo following the controversy. The publication stated that the executives are mad that Mayer’s company did not inform them sooner about the data breach. 

Ever since the massive 2014 hack was exposed last week, Yahoo is asked to answer questions left and right. Added to this hullaballoo is the lawsuit that was filed Friday by New York resident Ronald Schwartz. 

As previously reported, Schwartz is alleging in his lawsuit that the internet company failed to secure customer data because it did not implement basic data security protocols. Schwartz indicated that the affected user accounts are now “in the hands of criminals and/or enemies of the U.S.”