On October 29th, Vitalik Buterin, co-founder of Ethereum, said on social media in response to @0xgawswolf's personal attack asking if he was "retarded", "Yes." Note: "Retarded" is an English word that has traditionally been used to refer to people who are mentally retarded. However, the word is considered disrespectful and derogatory in modern use, and is therefore obsolete in many places.