Dannii Minogue's ex-boyfriend responded to people who had allegedly criticised him on the social networking site for unknown reasons.
"Who are u to judge the life I live? I know I'm not perfect And I don't live to be But before u point fingers make sure your hands are clean (sic)," he wrote.
"The d*cks on here only make me more determined and proud of who I am. Keep it up idiots.... I'm smiling...."
He then thanked the rest of his followers, saying: "Thanks to the great people on here... you make it worth while....".
Smith and Minogue confirmed their separation last month, after meeting in 2008 and becoming parents in 2010.
Soon after the announcement, the rugby player thanked his fans for their support following the break-up.
Minogue was recently revealed to have had a secret relationship with her X Factor colleague Simon Cowell in 2007.