yes, everybody has a right to filter and also the restrict readership.
what makes it perhaps a bit hypocritical as that twitter is supposedly a soapbox of free speech to the world, but that some people are not worthy of reading you.<p>So perhaps leave it up to the client software or don't be public about who you block and why (or perhaps do make your "killfile" and comments public). Personally I have never blocked anyone and assume the measure is made to make bullying and stalking more difficult. I don't see people who I disagree with not as such.