The human rights question?

So it is finally announced that the man shot dead by the police at the Stockwell Tube Station two days back is not connected to the recent London bombings. The whole incident turns murkier than before with this development. It is also revealed that the victim is of Brazilian descent, a country whose name popped up for the first time. The incident very crudely shows us how difficult it is to protect human rights in the face of terrorism. Such violations are rampant in many African and Asian countries. The explanation that is usually offered is the deeply rooted poverty and illiteracy that those countries are beset with although the large scale atrocities by the US army in Iraq and Guantanamo Bay can hardly be overlooked. The present incident is, in some sense, quite movie-like and also remarkable as it is committed by the most sophisticated and trained police officers, in full public view, in a cold blooded manner, and that too in the heart of London which is claimed to be a flag bearer of concurrent civilization.
I am reminded of a saying -- do not quite remember to whom this is attributed -- that there is always a danger that you yourself become a monster while fighting against them.