Thousands of webpages containing federal health guidelines and data went dark last week, only for some to reappear over the weekend without clarity on what had been changed or removed — and with disclaimers noting that the pages could be further modified.

A physician advocacy group filed a lawsuit Tuesday against federal agencies over last week’s purge of health information web pages and public health dataset, which they said harms patient care and | The removal of thousands of health information web pages and public health data streams harms patients and runs counter to health agencies' mandate,

The scientific community is showing signs of pushing back against President Trump's blackout and selective changes to federal health websites and datasets. Why it matters: That data has long been considered the gold standard in public health.

Tuesday's lawsuit names the CDC, FDA, and their parent agency the Department of Health and Human Services as defendants.