According to this WSJ report, the attacks breached computer systems and stole email. And the story gets better.
"The Chamber continues to see suspicious activity, they say. A thermostat at a town house the Chamber owns on Capitol Hill at one point was communicating with an Internet address in China, they say, and, in March, a printer used by Chamber executives spontaneously started printing pages with Chinese characters."
A thermostat communicating with an IP address in China?! The interconnected, M2M, IoT world--what's not to love?