New York City's subways — the biggest U.S. mass transit network — serve more than 6 million daily riders who depend largely on a signal system that dates back to the Great Depression of the 1930s.

Antiquated electro-mechanics with thousands of moving parts are still critical to operations. Dispatchers still monitor most trains from 24-hour underground "towers," and they still put pencil to paper to track their progress.

The Sony hack, the latest in a wave of company security breaches, exposed months of employee emails. Other hacks have given attackers access to sensitive information about a company and its customers, such as credit-card numbers and email addresses. One way hackers can sneak into a company is by sending fake emails with malicious links to employee inboxes. Here are five simple steps to make your email more secure and limit the harm a hacker can have:

ARCHIVE EARLY AND OFTEN

South Korea and Japan on Saturday vowed to work closely with the U.S. to combat cyber crime, after Seoul blamed North Korea for a crippling cyber attack on Sony Pictures.

South Korea said it would share with Washington information "related to the cyber attack on Sony," which it said bore all the hallmarks of an onslaught on its own banks and media agencies by the North last year.

North Korea called Saturday for a joint investigation with the U.S. into a crippling cyber attack on Sony Pictures, denouncing Washington's "slandering" after President Barack Obama warned Pyongyang of retaliation.

The U.S. blames the isolated state for the hacking which prompted the cancellation of the Christmas Day release of "The Interview", a madcap romp about a CIA plot to kill leader Kim Jong-Un which infuriated the North.

Andrew Steele, 15, chose a drone as a Christmas present. And he's not alone. Thousands of drone fans -- young and old -- turned out at a recent show in Los Angeles.

While historically people have thought of drones as military aircraft or flying devices used by businesses, the growth of drones as recreational vehicles has exploded.

South Korea on Saturday said North Korea had likely carried out a crippling cyber attack on Sony Pictures, which bore all the hallmarks of an onslaught on its own banks and media agencies last year.

Seoul said it would share information "related to the cyber attack on Sony" with the United States and step up international cooperation in coping with further online threats.

U.S. President Barack Obama on Friday warned North Korea it would face retaliation over a cyber attack on Sony Pictures and pledged not to bow to dictators, as an envoy for Pyongyang denied involvement.

Steve Wozniak says he is no fan of smartwatches and believes Google Glass will fail as he cautioned not to expect the company he co-founded, Apple, to always lead the way into new technologies.

The American, who quit Apple in 1987 -- 12 years after creating the technology giant with the late Steve Jobs -- made the comments as he took up Australian residency, with a view to living Down Under permanently.

Africa's first independent fact-checking website Africa Check, launched two years ago to promote accuracy in public debate and the media, announced Thursday that it had hit a million visitors.

Crossing the million mark "is symbolic for us", said Africa Check editor Julian Rademeyer.

A Federal Court in Canada on Wednesday ordered Apple's Canadian subsidiary to hand over nearly three years worth of documents to a watchdog agency as part of an anti-competition probe into iPhone sales.

The move comes after Canada's Competition Bureau last week said it was poring over Apple's contracts with local wireless carriers to determine if the company illegally stifled competition when it introduced the phone.