Brazil's largest Bitcoin exchange, Foxbit, is down for maintenance as R$ 1 million (~ U$ 300,000) have apparently gone missing.
In a live feed broadcast earlier today, Foxbit has discussed the issue and has reassured users that their funds are safe at this point, but that at least 130 suspected transactions are being investigated.
(November 2018 Update: A video previously located at https://www.youtube.com/embed/qdr0QcTH_1U has been permamently deleted.)
The exchange claims (previously linked to https://www.youtube.com/watch?v=qdr0QcTH_1U - video removed) to have enough liquidity to honor all customer balances even if it turns out the missing 30 BTC have indeed been stolen. Lost funds would be replaced by the company's own BTC reserves until the situation is sorted out.
Some customers who accidentally withdrew more than their balance have already contacted Foxbit to return the incorrect amounts, though it is not clear at this time how much of the total may be voluntarily returned.
The exchange has been down for 3 days now but has promised customers to come back to full operation by March 14.