A lot of speculation. There is no concrete proof it is even FH admin who was arrested yet, it just appears that it is the case. There is evidence that at the very least FH was hacked and had javascript exploits embedded in it that can deanonymize certain users who visit sites on it (users on Windows with old unpatched Tor browser with javascript enabled). The fact that FH having this attack code on it correlated with the bust of someone who is alleged to have hosted 100 CP sites with millions of images on them, and who it took the FBI a good deal of time to track down, strongly indicates but doesn't prove that the FBI somehow pwnt freedom hosting and somehow injected javascript exploits into it to target users accessing it, and that the busted dude in Ireland is FH admin. None of this has a shred of concrete evidence backing it up, and all of the news agencies reporting on it are literally reporting on rumors and speculation as if they are fact, it is actually rather disgusting watching the media report speculation as fact, they are doing a piss poor job as journalists and taking a gamble that they will be proven right in the future. Websites essentially consist of data files and programs running on computers, usually somewhat specialized computers called servers (although even a home PC is a server if it acts as one). In the case of Tor hidden services this is even more the case, as they don't rely on external parties to assign a domain name to them, and the key that essentially gives them their domain name is a file on the server as well. Take the server and you took the website, though other copies of it may exist on other servers and be able to go online in the future.