How? Poloniex disabled their wallets (that's quite normal and of course, I don't blame them at all) and we all know that keeping your coins on exchange is not that safe. Not to mention that the majority of ETH supporters are holding a lot of BTC on the exchange and they can build huge buy walls in a matter of seconds. Not sure how other exchanged reacted though.

P.S. I will say this for a 100th time that I have nothing against Ethereum, but some of the EF actions were not right. I am for a better future of cryptocurrencies and it doesn't matter to me who wins. What matters to me is their existence.