That hasn't worked yet for Wikileaks. If this worked and/or was the best way to deal with the types of problems Wikileaks is exposing, there would be no need for Wikileaks to exist.
The reason Wikileaks does exist is because, typically, when we attempt to address atrocities "democratically" we get nowhere.
On the other hand...
> Inventing a new currency that is, for a little while, hard to track by the government
This _has_ worked for Wikileaks in the past. When the US persecuted Wikileaks, Bitcoin helped to heavily negate the immediate impact of this action.
> The form that persecution takes is secondary.
In that case, why can't the form that Wikileaks' solutions take be secondary as well? If we are in agreement that Wikileaks is an important organization, then when addressing atrocities "democratically" fails, what would be wrong with short-term innovation?
The government is persecuting WikiLeaks financially because that is easy to do. Even if a cryptocurrency were to take off as a currency and still be untraceable, the government would just move on to some other form of persecution. The real problem to be addressed is the persecution of a useful legitimate organization by an ostensibly democratic government. The form that persecution takes is secondary.