Don't know why these brokers don't just release statements saying "we reserve the right to shut down trading when it looks like a really good scenario for our customers to make money".
EUR High Volatility Alert 2
With Greece’s uncertain future in the Eurozone continuing to dominate the headlines, we would like to inform you that we are doing everything in our power to reduce the risk of trading EUR pairs. In order to provide a safeguard against a highly volatile market open, trading on EUR pairs may be subject to increased margin requirements. This depends on the outcome of today’s decisive Eurogroup meeting, and how the situation in Greece unfolds over the rest of the weekend. Please be advised that, depending on the severity of market conditions come Sunday night/Monday morning, we reserve the right to limit EUR trading ... (full story)