They are working on a scheduled maintenance to replace the server. They have serious lag in the past weeks.
perhaps i spoke too soon -- had mini heart attack when i saw this
fyi - btcchina is back up and it looks like the downtime was caused due to a switch over to cloudflare for ddos protection; their ip is now being sourced out of europe -- things are looking up for them
perhaps i spoke too soon -- had mini heart attack when i saw this