There is a thread in reddit with multiple reports of Bitfinex users watching a malfunction occur, with massive long and short orders which they did not issue, and far exceeding the size of their account. It is being rapidly downvoted, and reddit is lagged.
http://www.reddit.com/r/BitcoinMarkets/comments/353yu8/bitfinex_having_serious_lag_issues_be_very/

If confirmed, I think there will be a bit of a holding pattern in the market until Bitfinex announces how they are going to clean up the mess.