If there were a checklist for China's "diehard lawyers faction" it would probably read something like this: Must be combative, dramatic, and have a flair for social media; must not be intimidated by authority; and must be willing to spend time under house arrest or in jail.

While there is no official group by this name, the term has evolved over the last few years to describe a particular type of criminal defense lawyer: brash, and determined to take on defendants whose rights, the attorneys believe, have been violated. The phenomenon came into sharp relief after the arrest of prominent Beijing lawyer Pu Zhiqiang (pictured above) on May 6 for allegedly "picking quarrels" by commemorating the victims of the June 4, 1989 crackdown on pro-democracy demonstrators in Tiananmen square in central Beijing. Pu remains in detention in Beijing, awaiting a hearing.

It all started with a case gone awry. Beijing lawyer Yang Xuelin, who identifies himself on social media website Weibo as a "diehard," told Communist Party mouthpiece newspaper People's Daily that the term originated from a discussion with another attorney in Guiyang, the capital of Southern China's Guizhou province, in July 2012. Yang and a colleague named Chi Susheng were part of a team of lawyers from around China who had come to the city to defend a former property tycoon accused of gang-related crimes. Over lunch on the first day of the trial, the paper explained, Chi complained the trial was already not going well. It was riddled with procedural problems, she said, and the team was going to have to "firmly fight to the bitter end," using the northern slang term sike -- which roughly means to fight to the bitter end, or to die hard. (The tycoon was sentenced to 15 years in prison.)

Since then, the term has been adopted by the lawyers themselves and become a convenient shorthand widely used by media and even Chinese authorities. On May 8, reliably nationalist outlet Global Times branded Pu as a member of this loosely defined faction in an editorial that argued Pu had "crossed the line" by attending a Tiananmen commemoration. (Pu, who took part in the 1989 demonstrations, has in fact commemorated them every year since.) The article also excoriated other so-called diehards. "These activist lawyers, who have wild intentions to challenge and change the law, have deviated" from what their jobs are supposed to entail, the editorial wrote. It leveled a warning at the group, who must "realize that they are not commandos or the authoritative forces" behind improvements to rule of law in China.

The commando metaphor is one both sides have embraced. An attorney from Xuchang, a small city in central China's Henan province, wrote on his blog that a diehard lawyer was someone who "goes deep into the mountains knowing well that there are tigers there." The tigers, he clarified, are officials, and not just any officials. In many of the cases championed by diehards, the corruption or abuse of power has been at the police or court level. In some cases, that means the tigers are the judges.

Many crusading Chinese attorneys have landed behind bars or been disbarred (or both) for defending marginalized groups which include practitioners of the banned spiritual group Falun Gong, Chinese Christians, or political dissidents. But those in the diehard faction do not necessarily focus their practice on dissidents. They take cases where legal rights are being flouted, regardless of the client. Their opponent is the court establishment, namely the police and even the judge. This adversarial stance has caught the attention of China's second highest justice. "We are now seeing a very strange phenomenon," wrote Shen Deyong, the executive vice-president of the Supreme People's Court, China's highest court, in a May 2013 essay published in the Communist Party-run People's Court Daily. "[Defense] lawyers are not in a confrontation with prosecutors, but instead are having confrontations with the presiding judge in the case," he complained.

That combative attitude is part of what makes a diehard lawyer -- so is showmanship. In a July 2011 murder trial in prefecture-level southern city of Beihai -- in which the victim was allegedly stabbed, but the autopsy found no stab wounds -- four of the defense attorneys who worked on the case were detained. One of them, Yang Zaixin, was jailed for nine months and then held under house arrest for six months for alleged witness tampering. (The charges were later dropped.) Yang's Weibo profile picture shows him posing on the enclosed balcony of the apartment where he was kept under house arrest, his fists up in the air like a winning boxer. Later, during the Guiyang trial, Chi, the lawyer who first coined the diehard moniker, collapsed as the judge tried to eject her from the courtroom and was taken to the hospital.

Diehard lawyers are also heavy users of social media, which allows them to stay in touch with each other and to advocate for their clients. Most, including Chi and Pu, have blogs or social media accounts and post frequently (though Pu's blog has been shut down). The constant posting means that plenty of inter-faction diehard squabbling, about what makes a diehard and whether membership should be formalized, also ends up online. Disputes aside, this is part of what makes this group a potential threat in the eyes of the Chinese government: Their refusal to keep a low profile and their potential influence on public opinion. An April 9 article posted to the website of the influential Communist Party journal Seeking Truth complained that diehard lawyers were "disrupting social order and undermining public safety," and called them a "poisonous cancer" on society.

The Chinese government is clearly worried about the so-called diehards’ impact, and is moving to trim it. Jerome Cohen, a professor of law at New York University, told Foreign Policy that the government is responding with an “increasingly repressive policy” that is trying to rein in the legal profession. Pu’s detention, Cohen said, is part of that movement. Although Pu is also considered part of the weiquan or "rights defense" school of lawyering and has represented dissidents like the activist artist Ai Weiwei, Pu straddles factions. And the repression isn't faction-specific.

Cohen said Chinese authorities are clamping down because they “want lawyers to behave like dentists.” In other words, the government thinks attorneys should be "good technicians and not involve themselves in cases of political-legal injustice.” But Cohen added that the crackdowns like that which ensnared Pu are only growing the ranks of “angry lawyers” in China, causing more to take up rights-related cases.

The outpouring of support for Pu on social media, from words of support to photos of him, does suggest that instead of weakening lawyers of his type, it is emboldening them. Another practitioner, Xu Tianming, wrote on Weibo that the "wanton arrest" of Pu would not work. The government should "not think that saying it diligently serves the people over and over" is enough. "In the Internet age," Xu concluded, "the people are their own masters."