About 11 hours ago
Poloniex transfered 30m BTS from their cold wallet to their hot wallet.

50% withdrawn in 11 hours
Since that transfer there has been withdrawals of 50% of these funds, 15 million BTS.
Not trusting Poloniex
I find it very fishy to set up an alert on the webpage stating that the wallet is in maintenance mode whenever their funds run low. And also stating that the issue "may require an update of the BTS team".
Sources: CryptoFresh