What are the big civil liberties and human rights law firms in the USA?
Are there any such law firms?

Thanks for the help guys and gals.

Not sure about law forms but there is on dearth of NGOs in the US working on these issues - like Human Rights Watch, Save the Children Alliance..... etc who look forth for legal officers to assist them (either as programme officers or as independent consultants).

I dont think law firms would look at these issues, unless you count some pro bono work in this category!