Four years later, I now represent more than 150 individuals and families who have lost loved ones in U.S. drone strikes. All of them – like Kareem’s brother and son – were civilians who posed no threat to U.S. national security. They were mothers, fathers, sisters, brothers and children who were going about daily life when the drone hovering overhead decided to rain fire. They are families who have turned not to guns, but to courts, to seek answers and have their voices heard.

Before I began representing civilian victims of U.S. drone strikes, I travelled regularly to the U.S. on a two year, multiple entry visa – a visa that was approved in three days. I worked as a consultant for USAID and even helped the FBI investigate a terrorism case involving a Pakistani diplomat.

But in 2011, when Columbia University invited me to come speak about my work with drone victims, suddenly there was a block on my visa application. I was told the Embassy had to send my application for “administrative processing” and they would contact me when they were finished.

Fourteen months later, and they still were not finished. I had long since missed the Columbia conference and now was about to miss a second one, this time organized by CodePink, the Center for Constitutional Rights and Reprieve. Repeated inquiries about the status of my application got me the same answer: it’s still being processed.

In April 2012, after more than a year of “processing,” I was finally granted a visa. I came to the U.S., met and spoke with people about my work. I thought the matter was settled.

I was wrong. Just over a year later, I am once again being denied entry into the U.S. because of my work on drone strikes. This time, the denial is to stop me from talking to Congress at an ad-hoc hearing on drones organized by members of Congress and Brave New Foundation. I hope to bring with me to the hearing Rafiq ur Rehman, who lost his 67 year-old mother in a drone strike, and two of his children, Nabila and Zubair, who witnessed their grandmother’s death and sustained strike-related injuries themselves. Both Rafiq and the children were granted visas. But I was not. Instead, my application was again put into “administrative processing,” where it remains to this day.

Without me, Rafiq and his children will not be able to travel and Congress and the American public will miss a critical opportunity to hear for the first time directly from victims of U.S. drone strikes. Rafiq won’t be able to put a name to the “militant” that was killed last October – his nearly seventy-year-old mother who was the only midwife for miles in his home village. Zubair won’t be able to tell why kids now prefer grey days to sunny ones – the drones don’t fly in bad weather. Nabila won’t be able to show her drawings of her home – all of which include a drone hovering overhead. And I won’t be able to tell you about the other families – or about the increasing anger I see drones generating among affected communities.

By blocking my visa, the U.S. government is once again keeping in the shadows a program President Obama promised only four months ago to bring into the light. A program that has now “covertly” assassinated upwards of 4,000 people in Pakistan, Yemen and Somalia – most of whom remain nameless, even to the committees tasked with providing oversight. This is a program that shows no signs of ending anytime soon. By refusing to grant me a visa, the U.S. government is trying to silence the 156 civilian drone strike victims and families that I represent. These families have lost children, elderly, mothers and sisters and are now trying through legal means to get justice.

Akbar, a lawyer challenging U.S.-led drone warfare in Pakistan, is legal counsel to Rehman, his family, and a growing number of drone victim families from Waziristan, in Pakistani Courts and the relevant governmental bodies. He is a legal fellow at Reprieve, an international organization fighting for justice across the globe, and heads the Foundation for Fundamental Rights.