Four Democratic leaders who sit in the U.S. House of Representatives Energy and Commerce Committee have written to Alphabet Inc demanding that they be briefed on Google Inc’s and Ascension Health’s deal by December 6. They are particular interested on how patient data that is stored on the cloud by the hospital chain will be accessed and used by Google.

Last week, Google’s cloud computing unit had made it lucidly clear, it has incorporated industry standard security and privacy practices into its deal with Ascension, and that none of the data is being used for advertising purposes.

Despite that House Energy Chairman Frank Pallone Jr. along with members Anna Eshoo, Diana DeGette and Jan Schakowsky, wrote in their letter that questions remain as to what data will be stored with Google, to what extent patients were informed about the companies’ agreement and which Google employees will have access to the data.