Every country's intelligence agencies with cyberwarfare components can detect hacking & other firewall breaches in real time, if one does manage to slip through they can backtrace hacking & firewall breaches & their origins right down to the terminal from the violators mainframe or a stand alone PC through it's IP address. Every branch of our military, the CIA, DIA, NSA, NRO, FBI, DHS & other alphabet agencies knew of this but it's politics, President Obama's a lame duck president so his threats are a matter of Russia's disrespect of America's electoral system while under his watch & he had to say something, Putin's not sweating any sanctions because he full well knows that Donald Trump will decertify anything President Obama declares. Business as usual.