TALLINN, Estonia - In the six months since part of Ukraine's power grid came crashing down, turned off by highly sophisticated hackers, cyberspace allies of President Vladimir V. Putin of Russia have been leaving their mark here in the Baltics and across the sea in Finland and Sweden.
New York Times: As Russian hackers probe, NATO has no clear cyberwar strategy
A woman sits on February 28, 2011 in Tallinn in front of a computer.
