Is it possible to hijack a chain by lowering the difficulty?
I should hope not, or practically every altcoin is in danger of attack. Otherwise, I seriously doubt they will ever be able to get the 51% hash required to overtake the BTC chain.
The question is : can you dedicate a pourcentage of your mining
BTC farm to win blocks on
BCC ... during only 1h after the change of the difficulty in the BCC chain (represent, for example, 3% of the actual difficulty of the BTC chain) ?
Now, you see ... it's only a question of mining device after all (win blocks and sell quickly after at any price).
That's why Mining industries like FORK.
To PUMP & DUMP on exchanges ... like all altcoins.