Once you have a solid money trail linked to a suspect bitcoin deal, you simply pounce when they cash out. Tracking bitcoins and other cryptocurrencies used in nefarious activities is such a booming business now that one of the largest in the space is a company called Chain Analysis. So perhaps true anonymity will always remain a distant dream. But there are others slowly trying to tighten the screws. For instance, there's a cryptocurrency called Monero that argues it's more private than bitcoin. And the new hot thing is another cryptocurrency called Zcash which claims it uses advanced tech to make sure that detecting ownership is nearly impossible.