OAKLAND, Calif.

The current $350 million ad campaign for the 2010 Census, including the much-maligned $2.5 million Super Bowl spots, urges individuals to “Tell your story.”

The Census Bureau is particularly eager for minorities and illegal immigrants to do so, as they are traditionally believed to be the most undercounted.

Yet widespread non-compliance, especially among those most likely to be discriminated against by a majority, may not be rooted strictly in the “ignorance” the ads are designed to overcome. History — including very recent history — shows that the information provided to the Census can be used against you.

The most recent examples occurred in 2002 and 2003, when the Census Bureau turned over information it had collected about Arab-Americans to Homeland Security.

Data from the 1940 Census were used to intern Japanese-, Italian- and German-Americans following the U.S. entry into the war, and to monitor and persecute others who escaped internment. In addition to providing geographic information to the War Department, the Census Bureau released the name, address, age, sex, citizenship status and occupation of Japanese-Americans in the Washington, D.C., area to the Treasury Department in response to an unspecified threat against President Franklin Roosevelt in 1943.

There may well be other instances of such data-sharing of which we remain unaware, as the full scope of the personal information released during World War II has only recently been brought to light.

Thus, while the Census Bureau assures us that “your confidentiality is protected. Title 13 requires the Census Bureau to keep all information about you and all other respondents strictly confidential,” these exceptions negate such assurances. Of course, the release of the “strictly confidential” data was also perfectly legal, during World War II, under the terms of the Second War Powers Act, and more recently, under the terms of the Patriot Act, now extended by the Obama administration.

In preparation for this year’s census, 140,000 workers were hired to collect GPS readings for every front door in the nation. Such pinpoint precision will certainly simplify locating any individual or group that may be identified as a threat to “national security” in the future. Remember, for example, the 1976 Senate Report in which 26,000 Americans were slated for roundup by the FBI in the event of a national emergency at the height of the Cold War. Now that the U.S. government’s Terrorist Watchlist has surpassed one million, the GPS data acquired could be instrumental in accomplishing such a roundup.

Meanwhile, the data are also shared a little more broadly than advertised. Stanford University recently joined the University of California at Berkeley, Duke, the University of Michigan, the University of California at Los Angeles and others in having its very own census data center.

As the director of the new center, C. Matthew Snipp, a Stanford demographer, explained, “The Census Bureau is very interested in making the centers more accessible to scholars who can use the data they provide.” As Henry Brady, dean of the Goldman School of Public Policy at UC Berkeley and principal investigator for the California Census Research Data Centers, helpfully added: “We’re trying to make centers where lots of federal agencies will let us use their data.”

While reassurances are repeated that the data are held under the strictest security, and will only be used for innocuous projects like “government programs and solutions to our problems,” do we really want academics to social-engineer policy solutions based on sensitive personal data? After all, they may turn out to be no more desirable than the “solutions” provided by government programs like internment and rendition. Without the protections afforded by a right to privacy, there’s little chance of escaping a political will to enforce discriminatory policies.

This “mission creep” for the Census thus pushes up against a level of discomfort no amount of advertising dollars can likely assuage. Many will no doubt choose to follow the advice of former U.S. Senate Majority Leader Trent Lott (R.-Miss.) to skip any census questions they feel violates their privacy, which may well include any exceeding the Constitution’s mandate for an “actual Enumeration.”

Unfortunately, choosing privacy now costs more: Legislation recently passed raises the fine for “anyone over 18 years old who refuses or willfully neglects to complete the questionnaire or answer questions posed by census takers” from a limit of $100 to $5,000 — a fact not advertised even in the small print..

Mary L. G. Theroux is senior vice president at the Independent Institute.