but zach harvey and his brother josh of manchester, new hampshire, are so convinced that bitcoin may become a crossover currency that at "bitcoin 2013," a conference later this month in san jose, they plan to showcase at atm for bitcoin. "there are really exciting businesses based on this. 'coinbase' conducts 15 million dollars' worth of transactions a month. it used to do a million a month. that gives you an idea of the growth of bitcoin." however, regulatory agencies appear to be closing in. in march, the treasury department concluded all firms that exchange or transfer virtual currency must report to the government and have policies to prevent money laundering. "the same people who want a decentralized internet currency now want a regulated, centralized currency. ultimately, that will be bitcoin's downfall, because you cannot have a decentralized, legal system of currency." as with many things in the virtual world, hacking into accounts is a concern, largely because the value of bitcoin has gone up exponentially. traded in 2010 at 3/10 of a cent, a single bitcoin is now valued at