A Bitcoin legal defense fund is a better place to start.  Your OP addresses people's right to use their computers to participate in the bitcoin network, a la possessing, transferring, and mining bitcoin.  That right is not under any sort of imminent threat of regulation, so no lobbying is necessary. 

There soon will be a "poster child" case made out by a U.S. attorney or state D.A. somewhere when some stupid college kid buys an ounce of coke with bitcoin and gets busted.  A Legal defense fund could help pay for his defense.  But the mainstream public face of the bitcoin community will be "Hang him high"  because it is in the best interest of bitcoin's survival in the mainstream as a real currency to appear cooperative with law enforcement.

However, lobbying certainly makes sense for a business like mtgox (Japanese-owned currency exchange) or silkroad that deals with exchanging bitcoin for other goods, services.  Now that the "press" has "hit the fan" and the word "Bitcoin" has publicly passed a prominent senator's lips, scrutiny and potential regulation will fall on these two organizations first.  These companies would do well to spend a significant portion of their profits on a lobbying firm to prevent legislation that would cripple their business model.