They can vote against people who write or enforce unjust laws. There's not much they can do about the judicial branch, but they only need to stop one branch.
That's the US anyway. I don't know the details about other countries.
If there's that much corruption, as opposed to people simply not voting for what they claim to care about, I don't think juries are going to be much help.
Another month has passed and here is a new rationality quotes thread. The usual rules are:
And one new rule: