a) If you could prove that these organisations were funding al Qaeda et al, shouldn't this be in a criminal court rather than a civil one?

It already has been criminal to a point. The families do have the legal recourse against the companies civily though. The burden of proof in civil court is less than that in a criminal court.

b) Does a court in America have any power to remove this sort of money from overseas entities?

No, not realy. Unless the international courts and the countries involved recognize it as such. But the US courts do have jurisdiction on some of the business's, individuals and banks based in the US. They have already seized monies and frozen accounts in the states. This is the money that the families are after. At least part of it. Also in other countries such as Britan, the courts are cooperating with the US courts to an extent.

c) Do international courts have the power to remove this sort of money?

It depends on if the countries recognizes the courts power. A country such as Lybia has been found guilty in international courts but nothing much has been done. About all they can do at that point is issue sanctions and hope that the UN or a coalition of countries will enforce it.

Without getting into a long discussion. Because a lot more is involved. This is the jist of it. Go check out CNN online. It has an in depth report on the ins and outs of the legality and actions of the families.........