There are protests, letters to the Prime Minister, online activism of every kind including the donation of one's profile picture to the cause, on Facebook. I have to believe that some of this, at least, must help.
Meanwhile, at least check out the Binayak Sen site, and read this article by C.P.Surendran (thanks, Vivek):
Dr Sen’s case is representative of the major failings of the Indian state, be it democracy, development or speedy justice. And none of it, typically, figures in these general elections. That no political party including the morally high-horsed Left has succeeded in mainstreaming these crucial issues is proof of a real problem.
But equally Dr Sen’s case also showcases a dire possibility that the worst can befall the best among us. Take care. One of these days you and I are just as likely to swell the rolls of the under trials. Don’t ask why. Shit happens. And in such an eventuality, unlikely as it may sound, the shame of our fate may outlive us, which was Josef K’s last thought as well as the knives went in.