Why is AlphaBay down

The authorities took down the Silk Road because its creator, Ross Ulbricht, accidentally revealed his real email address in an early online post about the site. Mr. Ulbricht is now serving a life sentence in prison for his role as the kingpin of the worldwide digital drug-trafficking enterprise.

AlphaBay operates much like eBay, hosting vendors who offer their wares and pay a commission to the site on each purchase. Customers deposit money with the site before making purchases. This is the money the operators could have stolen.

In 2015, the operators of the marketplace known as Evolution closed the site and took millions of dollars of users’ money.

Other sites have been taken down by law enforcement agencies in various countries using sophisticated techniques to unmask the operators’ anonymity.

In recent months, authorities in the United States have arrested several large vendors on AlphaBay who had sold synthetic opioids like fentanyl and U-47700.

In April, police arrested a couple in Greenville, S.C., who were allegedly connected to a popular vendor on AlphaBay known as PeterTheGreat. An 18-year-old in Portland, Ore., died after taking U-47700 that she bought from PeterTheGreat on AlphaBay, the authorities said.

When large dark net markets have gone down in the past, the transactions have quickly moved to other sites. AlphaBay currently has many large competitors, including sites like Valhalla and Dream Market.