CNET editor Dong Ngo has been involved with technology since 2000, starting with testing gadgets and writing code for CNET Labs' benchmarks. He now manages CNET San Francisco Labs, reviews 3D printers ...

Anyone who has been surfing the web for a while is probably used to clicking through a CAPTCHA grid of street images, identifying everyday objects to prove that they’re a human and not an automated ...

Snapchat added an image-based security challenge to its account registration process to verify that new accounts are created by humans, but the system can easily be defeated by computers, experts said ...

The images or characters you are often asked to fill in to prove that you are not a robot, are called a CAPTCHA. The term CAPTCHA stands for Completely Automated Public Turing Test to tell Computers ...