Wikipedia

Astroturfing is a form of advocacy in support of a political, organizational, or corporate agenda, designed to give the appearance of a "grassroots" movement. The goal of such campaigns is to disguise the efforts of a political and/or commercial entity as an independent public reaction to some political entity—a politician, political group, product, service or event. The term is a derivation of AstroTurf, a brand of synthetic carpeting designed to look like natural grass.

Astroturfers attempt to manipulate public opinion by both overt ("outreach", "awareness", etc.) and covert (disinformation) means. Astroturfing may be undertaken by an individual promoting a personal agenda, or highly organized professional groups with money from large corporations, unions, non-profits, or activist organizations. Very often, the efforts are conducted by political consultants who also specialize in opposition research. Beneficiaries are not "grass root" campaigners but distant organizations that orchestrate such campaigns.