Shares of Alphabet (GOOG) - Get Report edged down Monday amid a report that its Google subsidiary has teamed with one of the country's largest hospital systems on a secret effort to collect and crunch personal medical data on millions of patients across the country.

Alphabet was falling 0.92% to $1,297 after the Wall Street Journal reported that a team of Google employees has been collecting and analyzing the medical records of patients in 21 states where the St. Louis healthcare giant Ascension has hospitals.

Under "Project Nightingale," Google is collecting doctor diagnoses, hospitalization records and lab results, among other items, amounting to "to a complete health history, including patient names and dates of birth," the Journal reports.

Google is one of a number of tech giants that are making a big push into health care, with a skew toward data crunching, including Microsoft (MSFT) - Get Report , Amazon (AMZN) - Get Report and Apple (AAPL) - Get Report . The deal with Ascension appears to be one of the largest yet.

Google's aim is to use the data to design new software that would be able to zero in on individual patients and make recommendations for their care.

But patients and doctors have yet to be informed of the project, even as 150 Google employees have been able to access health data on tens of millions of patients, the Journal reported, citing people familiar with the issue and internal documents.

Ascension, in a statement sent out after the Journal story appeared, confirmed in a press statement that it is working with Google, but said the effort is fully complaint with federal medical privacy laws.

"All work related to Ascension's engagement with Google is HIPAA compliant and underpinned by a robust data security and protection effort and adherence to Ascension's strict requirements for data handling," the hospital network stated.

The statement did not address what types of medical and health data Google is gathering, but said one purpose is to "explore artificial intelligence/machine learning applications that will have the potential to support improvements in clinical quality and effectiveness, patient safety, and advocacy."

As part of its agreement with Google, Ascension will also upgrade its current technology platform by transition to Google Cloud, while also adopting Google G Suite "productivity and collaboration tools," the nonprofit healthcare provider said.

"As the healthcare environment continues to rapidly evolve, we must transform to better meet the needs and expectations of those we serve as well as our own caregivers and healthcare providers," said Eduardo Conrado, executive vice president at Ascension, in a statement.

Amazon, Apple and Microsoft are holdings in Jim Cramer's Action Alerts PLUS charitable trust.