Its network of deep roots, which make up more than half of the plant's biomass, makes it difficult to control with herbicides.

BBC: Invasive plant 'increases ozone pollution'

Microsoft has also formed the so-called Freedom to Innovate network, a "nonpartisan, grass-roots network of citizens and businesses" that happens to reside on the company's website.

CNN: ASIANOW - TIME Asia | Cover: 'Microsoft Enjoys Monopoly Power...'

Almost three decades later, he is chairman of Minnesotans for a Single Chamber and has gathered an impressive network of grass-roots supporters.

ECONOMIST: State legislatures

Howard Dean and Wesley Clark both made some efforts to build up a network of grass-roots volunteers in Missouri, partially through the internet.

ECONOMIST: A wide-open race now that Dick Gephardt has retired