I can see both side of this TBH.
Bitcoins are attractive to a small business like this due to the low transaction fees - but to the end user who wants to create a radio programme rather than become an ICT tech for finance (like me whose career path took me in exactly that direction!) its as labour intensive as paying your fees in any other foreign currency! OK maybe no worse or risky than online banking but still extra effort.
Some (not all) bitcoin mining is done using stolen resources and - the same greed fuelled tactics the conventional banking industry is berated for. however its becoming more resource intensive. but anyway if I had that many "spare" graphics cards (which you would have to purchase for conventional dosh anyway) to play with I'd use them to make cool pictures with instead :rofl:
As for anonymity, if you are making a sound broadcast then unless listeners are hidden in darkened mud huts using headphones its going to be heard by the "enemy" at some point and they will use conventional detection techniques to trace it. Detailed discussions of politics and sigint (two very complex subjects) are outside the scope of this forum but if there is anyone reading who wants to use sound broadcasting to put a dissenting political view in a "non western" country - my view is they would be no less unsafe and more effective doing it the "old style" way as a pirate broadcaster on analogue MF, HF or Band II (FM) radio frequencies!
Equipment to do this can be picked up using national currency for cash no questions asked or scavenged from other scrap electronic items (i.e comms kit for transport and public services) the target listeners need only a normal analogue radio to pick up the broadcast. not all poor dissidents are going to be able to afford computers or broadband or might need them for work and not want to risk them being confiscated, whereas an analogue radio can be obtained for €1-€5 nowadays and doesn't store incriminating data...
Also they can't be traced and identified (whereas because of the way internet radio works listeners are not anonymous) its how you get your pretty picture with a flag and sometimes a google map on centovacast.
Ironically these days most nations Communications Ministries (even "liberal" ones) have loads of young, enthusiastic staff devoted to monitoring and regulating the Internet (working with the civillian, military and covert security forces) and the net in many nations is designed to facilitate this monitoring, whilst the numbers of specialist staff who can trace an analogue pirate broadcaster are dwindling (especially outside city areas or where there are aerodromes and seaports where interference is a safety issue). The equipment they require is specialist and expensive too!
In the case of an analogue station run by rebels in one country, it would be feasible (barring jamming by the incumbent authorities) for sympathetic refugees in a neighbouring nation within reception range to pick it up off air and then retransmit it via an internet radio server to the refugees in further away nations. It may then be understandable the refugee community would want a bit of privacy to avoid reprisals.
Maybe bitcoin would work for this, at least in the short to medium term.
in the future though a wider issue is how much "controversial" content businesses running servers would want to host as stuff like tactical purchasing/product boycotts as acvitism works both ways in a free market economy, and increasingly the Communications Ministries will start keeping an ear out for what is heard online..