That is true, sure, but eventually those bitcoins can get converted into local Fiat currency or in USD and sent to an individuals bank account, paypal or to a credit card. In that case the banks or the government can ask questions about the origin of the money. If the OP was from another country he could maybe get a lighter sentence or a slap on the wrist but not sure what the officials in Iran would do in case you break their laws!
As you said, they've got PayPal and even through bank account transfer, they can show it as income from other sources or income for services (like create an account at a freelance site, ask a local person to post an ad for hiring someone and then apply and get paid through that website via PayPal) or just show it like they write articles/news for online news outlets and seeing the way OP is talking here, I don't think he's got some big amount of BTC to get changed them to his/her local currency. There are a lot of ways available, they can even ask to their trustworthy friend in another country where such laws are not applicable, and then ask them to send him/her the funds via any online medium or bank transfer as that can be shown as a gift.
