It was definitely a coordinated attack to crash bitcoin: http://www.reddit.com/r/Bitcoin/comments/1c3uqd/this_is_a_fucking_disgrace/ I can't find it now, but there was a blog post that talked about a whole bunch of $106 sell orders that were coming in when BTC was at $170 or something like that. So it was a combination of lag (which my or may not have involved a DDOS attack) and coordinated buy/sell orders to influence the price. It was certainly not the bitcoin community suddenly losing confidence in bitcoin en masse -- well, they did, because of the shenanigans, but not spontaneously. However, I've seen no evidence that central banks were involved. I think people are having a hard time accepting that random market manipulators could have done this. There's certainly financial incentive for virtually anyone to do this, not just banks.