I understand that there are horrible and crazy people out there in the cyber space that wants to abuse people but the problem I have with Twitter allowing its users to block other users is that it makes people I think less tolerant towards people who have different views from us and reduces our accounts to echo chambers. If somebody hasn't abused you personally or discriminated against you on a racial/gender/religious/medical etc basis then nobody should have the right to block someone else just because they have a different perspective or viewpoint. We should stand for pluralism and open mindedness