Michael Buckner/Getty Images A user on the BitcoinTalk forums has posted an extensive list rounding up the details on Bitcoin thefts since August 2010, well before most were paying attention to the digital currency.

Each entry includes the amount of money stolen (either an exact number or a reasonable estimate) and other details surrounding the thefts.

The entries total up to 818,485.77 stolen Bitcoins, presently worth some $502,081,166.11.

As there are currently 12.4 million Bitcoins in circulation, this means roughly 6.6% of the Bitcoin supply is controlled by people who came into possession of their digital currency by illegitimate means.

Put another way, one out of every 16-17 Bitcoins belongs to someone who stole it.

The most notable incident to date happened just recently at Mt. Gox, a Japan-based Bitcoin exchange that was for many people the default place to buy and sell Bitcoin. The company filed for bankruptcy protection after losing 750,000 of its customers' Bitcoins and 100,000 of its own, saying in a statement that it "believes there is a high possibility that the Bitcoins were stolen."

The missing currency was worth approximately $473 million at the time.

Bitcoin theft is generally enabled by poor password protection or other human carelessness. Those wanting to keep it secure long-term would do well to store their currency offline, in a physical Bitcoin wallet not connected to the Internet. This is analogous to keeping cash in a safe deposit box.