I personally believe that individuals should be entitled to hold moral values (whether I agree with them or not), and be able to act accordingly (of course, within the constraints of law, etc). In general I would even extend this principle to groups of people, but corporations should be treated as an exception to this "right" imho. One simple reason is the sheer clout they hold over our lives in this day and age. You start treating them like agencies that deserve the same rights as people and you run the risk of ending up with a society where the interest of corporations is supreme simply because they have much more clout that individuals do.
Of course I realize that US courts have usually held the right of a company to do business mostly as they please, but I think it is in general a bad idea. I will stick to my vision of the society I want to live in: let people decide what is moral for them; let elected representatives decide what should be illegal; and let corporations stick to doing business and not chose a "moral side" and force them to stick to the "legal side". Either what wikileaks did was illegal in which case the government/s could get a court order to make VISA and Mastercard to block donations to wikileaks, or it was not illegal in which case the government/s could just suck it up, or try rallying people's support to outlaw wikileaks.