This is a person who has been locked up into solitary for months now and is being treated very inhumanely. Is it because he hasn't written any Python libraries and isn't visible in Silicon Valley?
So argue that we should help Bradley Manning, or the inner city victims of the drug war, or children starving in Africa. But argue it somewhere else at some other time. Right now we have a cause. There are a large number of good people who want to fix this now. Let them. Help them. Because this needs to be fixed, and having a singular cause gives us focus. It puts success in reach, more than it is at any other time. You are not helping by distracting people with other serious problems -- all you are doing is making it less likely that anything gets done, by disheartening everyone with the scope of the problems we face.
We do not have to fix every problem in the world at the same time. Now is the time to fix this one.
I'd rather people calmly review the facts about the people and things involved with the situation rather than do the standard internet mob thing and call for heads to roll and people to be fired. Wait to learn the details rather than rely on emotions before you get angry.
And if you have an idea how to do that, let's hear it. Because "heads will roll" is not wholly without merit in these situations, but neither is it inherently the best possible solution. So if you can suggest something better then let's hear it.
But we still need to do something about excessively aggressive prosecutors too, because they can still do plenty of damage with knives and guns even after we take away their nuclear weapons.
Even at the level of "oh those are just diplomatic cables", those cables could just as easily have been "we need to focus on these nuclear weapons assemblies in Fooistan next" and tip off Islamist elements as to where to find their first dirty bomb, as of gossip about Berlusconi.
Bradly Manning has received plenty of attention in other circles. This site usually only deals with politics when it directly relates to tech.