This is just an idea, and not one I put much credence in, but worth mentioning as a possibility.
Looks like there was about 5 million Bitcoin that exchanged hands around the time Silk Road went down, and the Dept of Homeland Security seized MtGox's Dwolla account. The exchange rate in USD was around $120, so roughly $600 million USD exchanged hands. $600 million USD is a smitten of an investment for an entity that might be holding $100+ Billion in USD. There are many entities that could fall into this category: a bank, a government, or a large corporation. Heck, even a single man, like Bill Gates, has the capacity to drop $600 million pretty easily to protect the other $40 Billion. (For the record, I don't think Bill Gates would do this. However, a hedge fund that he knowingly or unknowingly has a stake in might.)
It looks like we are seeing prices drop on volumes below 100k Bitcoin per week for the last few weeks.
IF there was a large buyer of Bitcoin in May 2013, now trying to wear out the Bitcoin community, at this rate it will take somewhere between 1 to 1.5 years to burn through those 5 million Bitcoin.
This is just a cursory idea on a quick view of market stats - only looking at a couple key markets (MtGox, BitStamp). Any technicians out there have an opinion on this? I am sure the thought is fairly easy to credit or discredit.
Maybe not the govt, or Gates, but there is no doubt this is exactly what is happening. Endless selling by a huge holder that is in the black at almost any price. Selling, selling, selling, zero care about current market. Could be cold manipulation, could be criminal organization that just needs operating fiat, could be someone playing God, but I think we are in for two years of this crap minimum. Simply too few big dollar holders that can play God with their million BTC.