A little-known network funded by the Rockefellers, former Google CEO Eric Schmidt, and top foundations is behind a disruptive climate activist group that is drawing the attention of law enforcement, according to tax records.

Over the last year, an organization known as Climate Defiance has propelled itself into the national spotlight by deploying activists to blockade the Energy Department’s office in Washington, D.C., force a Democratic senator off the stage at her book launch event, and even storm the field during an annual baseball game featuring members of Congress. For these stunts, along with others, Climate Defiance activists have been arrested for the stated purpose of pressuring Democratic lawmakers to oppose the oil and gas industry.