if i am earning a good number of bitcoins i am entitled to pay tax in the form of online income in my tax returns and it is madatory to fill in the details regarding it. Since i am not earning any monatory gains at the moment i am not including it in my returns
i think that is not you are paying tax, you are just paying service charges, tax is only collected by the government, and government only collect tax on legal things, as bitcoin is not a legal currency therefore government is not collecting tax on bitocin.