By Christopher Dunn

As has been true for many lawyers, the attacks of 9/11 have had a dramatic impact on my practice.

Though my work before September 2001 already focused on the intersection between law-enforcement and civil liberties, the terrorist attacks substantially changed the types of controversies I faced as a litigator at the New York Civil Liberties Union and fundamentally changed the courts' approach to our work.

The attacks triggered a series of government actions, typically justified as counter-terrorism measures, that presented litigation challenges I led. These included an initial ban on protest marches after 9/11; heavy-handed policing of protests starting with the January 2002 World Economic Forum and extending through huge anti-Iraq War demonstrations in the spring of 2003; a nationwide NYPD surveillance operation of groups planning protests for the 2004 Republican National Convention; the subsequent arrest, lengthy detention, and blanket fingerprinting of nearly 2,000 protesters, journalists, and bystanders at the convention; the harsh treatment of Muslim families returning to the United States from a Canadian religious conference; the suspicionless searching of people entering the New York City subway system; and the detention and abusive investigations of people (usually Muslim-looking) innocently photographing public sites.

As much as the 9/11 attacks created a new set of civil liberties controversies, the attacks had a consequence equally significant for me as a litigator: They fundamentally changed the climate in the courts.

In the decade before 9/11, I litigated a series of high-profile First Amendment cases involving the Giuliani administration and the NYPD, and almost without exception Southern District and Second Circuit judges across the spectrum were receptive to our claims, notwithstanding their being directed at law enforcement. That all changed after September 2001.

Generally speaking, the judiciary is a conservative institution and becomes particularly so at times of threats to national security, as exemplified by the U.S. Supreme Court's endorsement of the criminalization of dissent during World War I and of the internment of innocent Japanese-Americans during World War II.

In our post-9/11 litigation, I regularly have been confronted with wholly reasonable judges who nonetheless are prepared to defer almost unquestioningly to law-enforcement officials and to distort or ignore well-established doctrine and precedent. In addition, in many of our cases the courts have embraced a level of secrecy that is unprecedented in my 25 years of practice.

Looking forward, it feels as if we are at a crossroads.

With the intensity of government response to 9/11 having lessened over the years, there may be a chance now to find a better balance between valid national security concerns and civil liberties.

On the other hand, should there be another substantial terrorist attack, we run the risk that the rule of law will be greatly diminished in our society.

Regardless, I anticipate that 9/11 will define my practice for many years to come.

Christopher Dunn is the associate legal director of the New York Civil Liberties Union.