The ostensible point of these sites is to give the public a quick way to glean the unsavory history of a neighbor, a potential date or anyone else. That sounds civic-minded, until you consider one way most of these sites make money: by charging a fee to remove the image. That fee can be anywhere from $30 to $400, or even higher. Pay up, in other words, and the picture is deleted, at least from the site that was paid.

To Mr. Birnbaum, and millions of other Americans now captured on one or more of these sites, this sounds like extortion. Mug shots are merely artifacts of an arrest, not proof of a conviction, and many people whose images are now on display were never found guilty, or the charges against them were dropped. But these pictures can cause serious reputational damage, as Mr. Birnbaum learned in his sophomore year, when he applied to be an intern for a state representative in Austin. Mr. Birnbaum heard about the job through a friend.

“The assistant to this state rep called my friend back and said, ‘We’d like to hire him, but we Google every potential employee, and the first thing that came up when we searched for Maxwell was a mug shot for a drug arrest,’ ” Mr. Birnbaum said. “I know what I did was wrong, and I understand the punishment,” he continued. “But these Web sites are punishing me, and because I don’t have the money it would take to get my photo off them all, there is nothing I can do about it.”

It was only a matter of time before the Internet started to monetize humiliation. In this case, the time was early 2011, when mug-shot Web sites started popping up to turn the most embarrassing photograph of anyone’s life into cash. The sites are perfectly legal, and they get financial oxygen the same way as other online businesses — through credit card companies and PayPal. Some states, though, are looking for ways to curb them. The governor of Oregon signed a bill this summer that gives such sites 30 days to take down the image, free of charge, of anyone who can prove that he or she was exonerated or whose record has been expunged. Georgia passed a similar law in May. Utah prohibits county sheriffs from giving out booking photographs to a site that will charge to delete them.

But as legislators draft laws, they are finding plenty of resistance, much of it from journalists who assert that public records should be just that: public. The Reporters Committee for Freedom of the Press argues that any restriction on booking photographs raises First Amendment issues and impinges on editors’ right to determine what is newsworthy. That right was recently exercised by newspapers and Web sites around the world when the public got its first look at Aaron Alexis, the Navy Yard gunman, through a booking photograph from a 2010 arrest.