[tor-talk] attacks on Tor hidden services

[Gozu-san]

Freedom Hosting <http://xqz3u...haeo.onion/> seems to be "#OpDarknet
Enemy Number One".  I've been monitoring its availability, and I'm
puzzled by the results.

So, I open a few instances of TAILS 0.8.1 routed via VPN services to
various exit IP addresses.  All of them can load my private test sites,
with typical delays of a minute or so.  However, all of them report
"Proxy error: 504 ... General SOCKS server failure" for the Freedom
Hosting site, and they do so immediately, with no lag.  These are LiveCD
instances, by the way, so there's no local Polipo cache.

Conversely, using an old Tor installation, freshly booted, the Freedom
Hosting site comes up, with typical delay of a minute or so.

What might be causing that behavior?