Just noticed this happening pretty recently, fairly major news for bitcoin
the IRS has decided that bitcoin is to be treated as property as opposed to currency, thus capital gains tax would apply. This page explains it better than I will be able to :) http://techcrunch.com/2014/03/30/bitcoin-slips-in-the-wake-of-the-irss-tax-decision/
This helps explain the drop in bitcoin price this week - from $560 to around $460 over the past 10 days http://bitcoincharts.com/charts/bitstampUSD#rg10ztgSzm1g10zm2g25zv
MEJ Price at posting:
6.0¢ Sentiment: Hold Disclosure: Held