The Danger Lurking Just Below Ukraine's Surface

The widespread use of mines has left Ukrainians scrambling to find ways to clear the explosives. New efforts to develop mine-clearing technology may help them push back Russia's invading forces.

They Cracked the Code to a Locked USB Drive Worth $235 Million in Bitcoin. Then It Got Weird

Stefan Thomas lost the password to an encrypted USB drive holding 7,002 bitcoins. One team of hackers believes they can unlock it—if they can get Thomas to let them.