Some altcoin got 51 percented and now bitcoin is at danger? 
Nothing has changed, bitcoin has always been vulnerable to it in theory.
Nothing has changed, bitcoin has always been vulnerable to it in theory.
I do not think it's real for BTC, show me a man who can buy as much power for an attack of 51%, it's impossible. Bitcoin Gold always has some problems and this is not the last. And why, then I'm not surprised that this is exactly what happened with this coin.