How the Census Works

Privacy and Security of Census Data

By law, the Census Bureau cannot share census answers with other government agencies, including welfare agencies, immigration, the police or FBI, the Internal Revenue Service, courts or the military. Under the provisions of Title 13 of the U.S. Code, census workers who break this law face up to five years in prison or $250,000 in fines or both [source: U.S. Census Bureau]. The law works — millions of questionnaires are processed without any breach of trust.

The law requires each batch of census forms to remain private for 72 years [source: U.S. Census Bureau]. This is to protect personally identifiable information from going public. The rationale is that little negative impact could happen after 72 years, since most of the people listed would be gone or were young children when it was collected. The process of microfilming and printing the census also takes a long time to accomplish by the sheer volume of documents. (This process usually takes another two years or so to complete and make ready for the public, according to bureau officials.)

In 2012, the bureau released data from the 1940 census and posted it online through the National Archives. The complete 1950 census records will be released in April 2022 [source: U.S. Census Bureau].