Or they may just mint their own cryptocurrencies

I'd guess talking to your local political representative might be a valid step normally, but I see that the central bank in Bangladesh went as far as to request citizens not to “spread information about it.” so you are not even supposed to tell anyone.

http://bitcoinist.com/bitcoin-still-illegal-six-countries/

There is an old saying attributed to Benjamin Frankin that "Nothing is certain but death and taxes". Bitcoin doesn't do anything for the risk of the former but governments are concerned that it bypasses the latter. It won't make you popular, but if you can tax them that will make governments much more amenable to them.

Γενικά μπήκε πάρα πολύς κόσμος τον τελευταίο καιρό και δεν μπόρεσαν να ανταπεξέλθουν οι πλατφόρμες. Συνεπώς θα πρότεινα να μην κρίνουμε με βάση τη συγκεκριμένη περίοδο. Τώρα ενισχύονται και σύντομα θα λειτουργούν πολύ αποδοτικότερα.

There is currently a huge congestion in BTC payments. The network is flooded and the transaction costs go up (supply and demand). You could check before making a transaction here:

https://blockchain.info/unconfirmed-transactions

Don't tell me - you searched https://archive.org for Satoshi Nakamoto for the dates before the famous paper 

Well the first thing they would do would be to just freeze all bank accounts (with all their money in them) that interacted with any cryptocurrency by sending or receiving funds. That would isolate cryptocurrencies.

Remember how while Thomas Gresham's Royal Exchange founded in England in 1571 brought immense financial wealth into a small country previously dependent on wool trading in many other countries (maybe all) financial regulation prevented the growth of industry and trade - for example many branded charging of any interest as usury.

So they may not think out the benefits before locking themselves out from them.

I think there has been a concern about currency circulating without the government being able to tax it. A second concern would be the ability to move currency (and therefore wealth) out of the country without the government being able to control or restrict that.

That's actually quite a cool application of blockchain. Could it be applied to monitor other mechanical wear or even automotive applications (oil changes, service history or wear life relating to engine revs). And how about tachographs?

Thanks. DAG looks interesting - how parallel is it?

"fear based talk" - I guess I'm not a particularly panic based person so that doesn't worry me. I'm looking for a coolheaded assessment of the level of resources needed to undermine specific systems through a 51% attack. This calm approach allows us to think of solutions. So it's not "fear based" any more than any other cryptographic threat assessment is.

I'm specifically thinking that if you can afford the resources to be doing 51% of all the mining, you can subvert a blockchain. You might want to do this if you had currency exchange barriers and individuals where moving funds using cryptocurrencies. For example which governments or organizations could afford to do this? What might be the consequences?

What would you say the fastest, smallest distributed ledgers are? How do they gain those advantages?