Same problem here. Bitstamp, BTC-e, and Bitfinex give me that error, but Huobi does not. Logging out doesn't help.
I have the exact same issue where only Huobi works. A friend I believe in NL or BE said that its working fine for him today (1 hour before this post). I wonder if someone mistyped some IP filter and blacklisted ARIN addresses or maybe they just did not want the NSA to be able to incorporate their charts into PRISM
