A database of 1.4 billion user passwords compiled from 252 data breaches is suspected to be the largest ever.
Criminals are migrating to the dark web on a massive scale, Europol warns.
It is not clear why websites including the popular Dream Market suddenly disappeared.
Manhattan federal prosecutors have seized $48 million from Robert Ulbricht, Silk Road creator.
The records come from at least nine states, and the seller claims to have more.
A bitcoin wallet attached to the site has already received donations worth more than $87,000.
Illicit drug transactions on the dark web have increased significantly since 2013.
Mozilla says the Firefox vulnerability, which the FBI won’t disclose, leaves millions of its users vulnerable.
Inside the Web's secret space for drug dealers, arms traffickers, hackers and political dissidents
Libertarian surfer dude Ross Ulbricht built his cyber drug cartel, Silk Road, on a belief in free markets and Internet privacy. Now he’s in prison for a very long time.
The fall of the Silk Road has led to a proliferation of smaller 'dark net' virtual marketplaces