Yesterday, in response to this week’s indictment of a 24-year-old Harvard researcher and Internet activist for allegedly hacking into MIT’s network and collecting nearly five million scholarly articles, a second hacker released more than 18,592 (32 gigabytes) of subscription-only research obtained from the same service. The second man identified himself as Greg Maxwell, a 31-year-old “technologist, recreational mathematician, and scientific hobbyist” from northern Virginia.

The Harvard researcher, Aaron Swartz, was indicted on federal charges of downloading articles from the nonprofit online academic database JSTOR last year. Swartz is a prominent programmer who founded a company acquired in 2005 by Reddit, and a fellow at Harvard’s Center for Ethics. In a 2008 “Guerilla Open Access Manifesto,” Swartz called for activists to “fight back” against services that held academic papers hostage behind paywalls. “We need to download scientific journals and upload them to file-sharing networks,” wrote Swartz.

Maxwell says he released the papers for similar reasons. He says the papers come from the Philosophical Transactions of the Royal Society and were published before 1923, which means they’re in the public domain (his claim has not been independently verified). “This knowledge belongs to the public,” he argues. For the sake of scientific progress, Maxwell says, such databases shouldn’t keep research under lock and key at all, let alone beyond their copyright expiration, as is the current practice. “Progress comes from making connections between others’ discoveries, from extending them, and then from telling people,” he says.

Though Swartz voluntarily returned the data to JSTOR, and MIT did not seek legal action, he could nonetheless face up to 35 years in prison and $1 million in fines as a result of the federal indictment. No charges have yet been brought against Maxwell.

Swartz’s arrest, and Maxwell’s actions, are part of a broader trend of digital vigilantism. Swartz’s arrest has also sparked debates on access to information and on what some see as the government’s extreme reaction. That government response may itself be a reaction to a spate of recent attacks on Sony, Citibank, and numerous government departments by the hacker collectives LulzSec and Anonymous—and by the release of thousands of classified government documents by Wikileaks.

“I think there’s a lot of room for online protest,” says Mark Rotenberg, executive director of the Electronic Privacy Information Center in Washington, D.C., “but that doesn’t mean that what people do online, even with good intentions, may not cause harm to others.”

In a press release, Carmen M. Ortiz of the United States Attorney for the District of Massachusetts, said: “Stealing is stealing whether you use a computer command or a crowbar, and whether you take documents, data or dollars.”

Proponents of information freedom and of undermining censorship are increasingly turning to more radical means of making a point. But critics say that their actions could cause problems for others. “Part of the true protest tradition is people making some sacrifice of their own so that others may benefit,” says Rotenberg. But he warns that, in recent cases of hacktivism, “there may be some innocent bystanders hurt in the process.”