Its larger than AlphaBay.

See Operation Bayonet, which became public on july 20 2017:

https://www.europol.europa.eu/newsroom/news/massive-blow-to-...

Wikipedia might have more information as well. Regarding AlphaBay:

https://en.wikipedia.org/wiki/AlphaBay#Seizure_and_shutdown

What I personally found interesting about the whole story (which was widely covered in Dutch media, since the police is (rightfully, IMO) proud of their accomplishment) is how the Dutch police were able to keep a darknet site called Hansa running for nearly a month after the servers were seized. The German police arrested the administrators, while the Dutch police moved the servers to Dutch territory, and made them operational again. They then tried to keep the site running, so they could analyse the logs, traffic, and visitors.

Interestingly, the Canadian AlphaBay administrator was residing in Thailand and was logged in at that moment to keep the site running because there were some (artificial) technical difficulties. I'm curious how those were started. If you don't want to confiscate the server, but know where it is, it should be doable to -for example- do massive traffic shaping on the link to make it seem like there's a DoS attack.

AlphaBay was a darknet market. As you might expect, it trafficked in illegal goods. Since authorities seized it and shut it down, they've been able to read the site's data, and can now prosecute all sorts of illegal actions that happened there.

They didn't shut it down immediately, they run it for a few weeks collecting information.

It's quite likely that they've used it to either directly compromise or unmask real world assets of it's users beyond what would be possible from just reading some logs.

Quite likely, though the logs would be immensely valuable on their own.