Last week\u2019s theft of $90,000 in Bitcoins from the Bitcoinica website is beginning to\u00a0look a lot like an episode of\u00a0Law & Order.\n\tBackground: Bitcoins are a virtual currency that's pretty much impossible to trace. The FBI and others are concerned\u00a0Bitcoins could be used for criminal purposes. Bitcoinica is \u201can exchange that enables leveraged speculation in its contract-for-difference market against the Bitcoin to USD (BTC\/USD) exchange rate. The service charges no trading fees but instead earns from the trading spread -- similar to how forex trading functions.\u201d\n\tOn May 11, Bitcoinica's 17-year-old founder, Zhou Tong, posted on the Bitcointalk blog that the virtual bank\u00a0had\u00a0apparently been robbed:\u00a0"Today, we have discovered a suspicious Bitcoin transaction that doesn't seem to be initiated by any one of the company owners. Some of them are not online at the moment so this is not conclusive,\u201d he wrote.\n\tThe attack happened two weeks after Zhou\u00a0dropped the reins of\u00a0Bitcoinca\u2019s daily operations, and he sold the company to an undisclosed investor back in November 2011. The new owners posted this on the site:\n\t\n\t\t"The overwhelming majority of our bitcoin deposits were not stolen. The thief stole from us not you. All withdrawal requests will be honored."\n\n\tThe post also said a database of user names, e-mail addresses and account histories was accessed and some encrypted data may have been compromised. It urged customers who reuse their Bitcoinica passwords on other sites to change them and also\u00a0added:\n\t\n\t\t"Even full access to website database would not give the attacker access to this data. We will have more to say soon about the circumstances surrounding this attack and what we will do to handle it."\n\n\tZhou later posted in an online forum that\u00a0hackers had broken into a Rackspace-hosted server\u00a0after they managed to reset a password, most likely through an automated e-mail. And\u00a0Zhou\u00a0said he will retire from all bitcoin-related projects after this incident is resolved.\n\tThe reasons why Zhou sold the company are unclear, to say the least. In the related post, he wrote, "In November, an investor approached me to acquire Bitcoinica. Due to regulatory concerns, I agreed to the deal and signed the agreement.\u201d He also said he sold it for a good price. However, earlier in the post\u00a0Zhou said that after just a week of trading on the site, \u201cvolume passed one million dollars. I started making profits like crazy.\u201d\n\t\n\t\t"It feels great to have an experimental project become the 'best thing since sliced bread,' and run one of the most profitable businesses in a new economy. Bitcoinica has a total historical revenue equivalent to about 0.67% of the whole Bitcoin economy. Not even Apple can match this record in the real world economies."\n\n\tDoes that sound like a\u00a0person who wants to sell his company? Zhou was not only the\u00a0Bitcoin\u00a0president and inventor, but also\u00a0its sole employee.\n\tIt is also worth noting\u00a0that\u00a0the latest incident is the second\u00a0Bitcoinica robbery in 10 weeks. In March, attackers\u00a0stole 43,000 bitcoins after they compromised servers\u00a0provided by\u00a0Web-hosting\u00a0company Linode.\u00a0A single\u00a0bitcoin is currently worth around $5, so that\u2019s a lot of electronic dough.\n\tYou can\u2019t call in the cops because no one has any jurisdiction here. If you were the police and you were investigating, who would be your primary suspect?