The anonymous online black market known as the Silk Road, which offers everything from drugs to pirated Red Bull, is back up after an outage that lasted about two weeks.

When Silk Road became inaccessible earlier this month, the rumors started flying. Its psuedonymous operator Dread Pirate Roberts was temporarily incommunicado, prompting theories that he’d been picked up by the FBI or had run off with the site’s deposits. There were also claims that the site had been hacked, or flooded with fake traffic and brought down by a malicious attacker.

Silk Road started coming back online late last week and is now running, albeit slowly and with some errors. Dread Pirate Roberts reassured users that there was no scam, no FBI, and no hacking. The illicit bazaar was growing so fast that the influx of new users brought the site down, he announced.

"We were getting an influx of new members that was overloading our current infrastructure."

"A couple of weeks ago, we started seeing the accessibility and speed of Silk Road start to drop, especially around peak hours," Dread Pirate Roberts announced to Silk Road users in a forum message. "Monitoring the number of incoming connections, pageviews and registrations showed record breaking numbers, so the obvious conclusion was that we were getting an influx of new members that was overloading our current infrastructure."

Dread Pirate Roberts and Silk Road’s team, which includes technical as well as customer support, "did a full redeploy of the entire system including the new security and performance measures which turned out to be quite challenging in the end," Dread Pirate Roberts said.

Although the explanation was short on details, most users gladly accepted it and seemed to have resumed their normal illegal activities. "Just like that. Faith was returned to the road. Thanks DPR," wrote user luckysquid.

Silk Road is only accessible via Tor, a decentralized network of servers that encrypt and relay signals in order to mask users’ online activity. The vast majority of listings are for drugs: prescription opiates like Oxycontin and anti-depressants, steroids like Somatropin, and street drugs including marijuana, ecstasy, heroin, cocaine, and even the notorious date rape drug GHB.

Users rely on Bitcoins, the semi-anonymous ecurrency, in order to buy and sell the thousands of items on offer; it’s been estimated that the marketplace accounts for a majority of all commercial transactions done in Bitcoin.

Nicolas Christin, associate director of the Information Networking Institute at Carnegie Mellon University, spent six months tracking activity on Silk Road and released a report in August estimating the marketplace’s activity at around $22 million from January to July of 2012.

The study made quite a splash, although the $22 million figure turned out to be a bit high. Dr. Christin will be publishing a revised version later this month that lowers the estimate to around $15 million.

Silk Road had at least $15 million in business from January to July

The true figure is still elusive. Dr. Christin’s estimates do not include stealth listings, which are not linked from the rest of Silk Road and are only viewable to buyers who have been given the URL. He also stopped tracking sales in July, after which the site has reportedly grown significantly.

Dr. Christin is inclined to believe the official explanation for Silk Road’s temporary disappearance. "Server overload, basically, due to the continuous, rapid increase of members, which led to the site being unusable. They had to redesign their infrastructure to accommodate the load; not an easy thing to do given their security constraints," he said in an email. Although he acknowledged that the reasons could be more nefarious, "the explanation given by the operator is consistent with what could be observed."

Tor has stymied the FBI’s efforts in the past, putting a stop to at least one investigation into child pornography. However, users have reason to be paranoid. US senators Chuck Schumer and Joe Manchin publicly called on the Drug Enforcement Agency to investigate Silk Road last year.

In April, the feds busted the Tor-protected drug marketplace known as The Famer’s Market, arresting 15 people. In August the Australian Federal Police arrested a man for importing drugs using Silk Road, issuing a warning to Silk Road users that "their identity will not always remain anonymous and when caught, they will be prosecuted."

The DEA says it is investigating Silk Road

The DEA says it has been investigating Silk Road for more than a year. When The Verge called to ask about Silk Road, DEA spokesperson Rusty Payne recognized the name immediately. "Typically we’re not really giving out investigative updates about what we’re doing, but it’s it's safe to say we are heavily involved in looking into that."

It’s been pointed out that Silk Road is tiny compared to the worldwide drug trade, suggesting that authorities should concentrate their resources elsewhere. Still, the site’s fast growth, and the terror that the "world weed web" strikes in the hearts of first-world parents, make it an increasingly attractive target.

But for now, at least according to the site’s operators, robust IT support remains the biggest challenge.