(Update 2017.08.01) Be aware! There have been a Bitcoin Blockchain split, resulting in two chains: bitcoin.org default chain and "Bitcoin Cash" chain. As per our original plan outlined here, all of our facilities are following the original bitcoin.org blockchain. We will not register transactions that you send to your addresses on the "Bitcoin Cash" blockchain. We cannot make withdrawals to any "Bitcoin Cash" addresses.
Bitcoin Fog blocksize-fork policy:
TL;DR; Bitcoin Fog will keep running under Bitcoin Core (bitcoin.org) implementation in an event of a fork. The post-fork value of your Fog wallet remaining in the forked blockchain (presumably Bitcoin Unlimited) will be transparently sold for the Bitcoin Core-currency at the market price (at a point in time to be chosen at the sole discretion of Bitcoin Fog crew) and added to your Bitcoin Core-denominated balance held in the Fog. In case this policy changes, Bitcoin Fog will warn 30 days in advance.
The Bitcoin community has been talking about a possibility of a fork in the near future. There are some disagreements within the community as to how to handle the challenges of scaling the Bitcoin network to be able to handle the level of popularity it has gained. There are different solutions promoted by different actors and both the chances and the outcomes of a fork are unclear. If a fork will happen, there will be multiple distinct versions of the Bitcoin network running simultaneously. All of the forked networks will share the same transaction history prior to the time of the fork, but after it the transactions will completely diverge. In order to plan ahead you need to know what will happen to your funds held in online wallets such as Bitcoin Fog.
Bitcoin Fog has taken into consideration the arguments of both sides and have estimated that Bitcoin Core is the way forward. In case there will be another blockchain that will be most widely used, we might implement it in the future, as an extra currency, or in some other way. However, at this time we are staying with Bitcoin Core and we believe that this is the choice that most of our users agree on. In case of a fork, Bitcoin Fog will keep funds in the Bitcoin Core blockchain internally. Since your funds held in our wallet will likely have some value in both of the new blockchains, we will manually sell the Bitcoins in the forked blockchain for the Bitcoin Core-bitcoins, and redeem the users with the exchanged amount. The exchange will happen within the first weeks after the fork. The exact date (and thus the exchange rate) will be chosen by us.