A quick check of the database confirms that it is indeed imperfect. Some records are incomplete, and there is often no way to distinguish between people with the same names if you don’t know their birthdays (and even that date is often missing).

To further test the site, I vetted some of my colleagues at The New York Times. One, who shall remain nameless, had a recent tangle with the law that the site labeled a “criminal offense,” while adding no other information. Curious, I called my colleague with the date and city of the now very public ignominy. The person was stunned to know that the infraction  a speeding ticket  was easily accessible and described as criminal.

“I went to traffic school so this wouldn’t appear on my record. I’m in shock. This blows me away,” my colleague said, demanding that I ask PeopleFinders how to have the record removed. “I don’t necessarily want you all knowing that I’m a fast driver.”

PeopleFinders’ response: take it up with the authorities. When they update their records, the change will automatically appear on CriminalSearches.com.

My colleague’s quandary illustrates why privacy advocates work themselves into knots about this kind of site. In the past, Congress carefully considered how the public should use criminal records. Amendments to the Fair Credit Reporting Act in 1997 required that employers who hire investigators to obtain criminal records from consumer reporting agencies advise prospective employees of the search in advance, and disregard some types of convictions that are older than seven years.

“I don’t think Congress stuck that in there randomly,” says Daniel J. Solove, a professor of law at the George Washington University Law School and author of “Understanding Privacy.” “Congress made the judgment that after a certain period of time, people shouldn’t be harmed by having convictions stick with them forever and ever.”

BUT now, of course, none of the old restrictions apply. The information is available from a variety of sources, and now free. Jurors can and almost certainly will be tempted to look up criminal pasts of defendants in their cases. And employers can conduct searches themselves without hiring investigators. Mr. Lane of PeopleFinders says that employers cannot legally use the database in making hiring decisions  but there is nothing to stop them.