Anonymity allows people to release their opinions free without any consuquences. And that could help in politics or just simply everywhere else where people might be scared of the backlash that they may recieve just for stating their opinions. Thats a reason i simply believe that anonymity should be a human right.
Anonymity, especially amongst large groups, can cause what is caused deindividuation. This is where individuals become less about themselves, and start becoming more a part of a group. This is what we witness in mobs - people lose themselves and often lose the accountability that comes with acting as an individual. So in fact, anonymity can actually have the opposite effect of letting people realise their own opinions - they are more likely to agree with the opinions of the group majority than think for themselves. Certainly it is important for people to have the right to say their opinions without fear, but anonymity is not the answer. This is where we get internet bullying - trolls hiding behind a key board.