This article relates to the use of Bitcoin on the "deep" web where a lot of people use TOR to surf. The negative publicity about Bitcoin in this article would given even some of its most stauntious supporters pause.
"From online drug bazaars to virtual currency tax shelters, the growing anonymous web has many corners of Washington concerned"
"The policy problem is compounded by Bitcoin, which represents another set of jurisdictional tangles for Washington. The Senate Homeland Security Committee, officials tell TIME, plans on holding hearings on Bitcoin within the month."