Why is yahoo censoring people like north korea does its citizens?

I am so tired of the censorship on this site, i am just curious as to why it is done. I cant post a website, i cant speak against things in my own fashion. I have to code it, or hope that yahoo misses me. Reminds me of 1984...some one will say, why do you stay then. Becuase regardless, i am still getting across to my audience.