The FRN server, oddly enough, is physically located in Joplin MO, and the site is registered to John Cruzan, who founded it and supported it for years. He and Kirk Trummel set up the site originally as a dial-in BBS in the 90s, and later converted it to a web site in 1998 or so. Both were active pirates, up until they got a visit from the FCC in the late 90s.
However, Kirk died, and Cruzan went on to bigger and better things. In the early part of the last decade Cruzan gave control of the site to the group that now runs the new Google Free Radio North America group; however, the new crowd does not have physical access to the server, and Cruzan kept control of the domain name. This means that, if anything happens to the site that can't be fixed remotely, Cruzan must take care of the situation. This has caused outages in the past, due to things such as the domain name expiring. Last spring a huge tornado went through Joplin; the server was not directly affected, but, again, the FRN was cut off from the net for an extended period until Cruzan took care of it.
I do not know for sure what the current problem is; the FRN software is ancient and apparently extremely fragile, so perhaps it exceeded some limit, or maybe became corrupted somehow. There may be a hardware issue, or perhaps the hosting site changed in such a way that the software couldn't deal with it. In any event, it is up to Cruzan to fix the problem, and until then the FRN will probably stay down.
Something like this happened a number of years ago, and Cruzan told people that the FRN was not worth the trouble it took to maintain it, and he was going to let it go. Apparently, though, he got enough of an outcry from the membership that he went ahead and fixed the problem, but for a while there it looked like the FRN was history. The handwriting was on the wall, however, as it became clear that the site was probably going to go down at some point, irreparably, if Cruzan could not or would not fix it again. That time may be now.