No, I dont think photos can change the world, they can show a few people some things maybe they didnt know about or something like that but people are usually too lazy or self centered to even bother to do anything and those that do are usually looked down upon by those with too much time on their hands. Remember that lady that staked out in front of Bush's ranch of all that time, guess what, in the end it didnt mater, Bush is still in power, nearly everyone hates him (Especially here in china...) and thats the end of that.
Look how tame we all have become.