Is it possible to manipulate the difficulty increases by removing hashing power prior to the change? How is the next difficulty level set? Average over a number of blocks? Just looks like 100TH dropped off the network today just before the increase and I'm sure we will see the power back online immediately after the difficulty gets set.
It is possible to manipulate the difficulty increases by removing hashing power prior to the change, but you will make less BTC this way. The 100TH dropped off the network today is probably just variance (unlucky not finding new blocks as expeced)