(Photo by btckeychain)

The feds have taken on one of the darkest corners of the Internet: Silk Road, the online marketplace for bitcoin-fueled drug transactions. On Tuesday, FBI agents arrested Ross Ulbricht, the alleged owner of the service. Exactly how large this digital economy is has not been revealed, though researchers have certainly tried to estimate it. But in the government's criminal complaint against Ulbricht, we now have some stats to help flesh out the scope of Silk Road's online presence. According to federal authorities:

1. $3.6 million. That's the value of bitcoins seized. The government is calling it its largest bitcoin haul ever.

2. 957,079 user accounts as of July 2013. Some users might have had multiple accounts, but the government says the site may have had "hundreds of thousands" of unique users.

3. 9.5 million bitcoins changed hands over a five-monthtwo-year period. At current exchange rates, they're worth $1.2 billion.

4. $80 million was how much Silk Road earned in commissions from those sales.

5. $3.4 million was how much money Ulbricht had in his Silk Road wallet when he was arrested.

6. 1.2 million private messages were exchanged on the service during a two-month period this year.

7. Between $1,000 and $2,000 a week. That's how much the Justice Department says Ulbricht paid assistants to help administer the service.

The complaint paints a profile of a massive drug trafficking organization whose dismantling could  put untold drug traffickers in the offline world at risk of criminal charges.

Correction: The original version of this post said 9.5 million bitcoins changed hands on Silk Road over a five-month period from Feb. 6, 2013 to July 23, 2013. The period was two years, from Feb. 6, 2011 to July 23, 2013.