I'm cautious about your Latvia story - its sounds to me like the bike was worried about fraud. Thats pretty common - about half the times I go to the US, I have to ring up the bank and get the card unblocked.

That being said, there are countries attempting to control the flow of money. Argentina wants to enforce its price for the dollar. Cyprus wants to prevent everyone taking their money and running. and so on. However, most of these countries see attempts to circumvent their controls as illegal. I feel its unwise to get my hopes up about bitcoin for this sort of transaction for that reason.