An anti-fracking group that includes such celebrities as Anne Hathaway, Alec Baldwin and Yoko Ono may be breaking the law in its zeal to help ban fracking.

Artists Against Fracking has spent an undisclosed amount of money to influence drilling legislation in New York, saying the practice is bad for the environment. The group has a TV ad starring Yoko Ono and an anti-fracking athem called “Don’t Frack My Mother” featuring several of its celebrity members.

The problem is that the group isn’t registered as a lobbying group with the state of New York, even though its events and website appear to have cost well above the $5,000 threshold for disclosure, the Associated Press reports.

The group’s website  directs donations to the Sustainable Markets Foundation. Although the foundation’s donations are recorded publicly, it isn’t registered with New York as a lobbying client either, according to AP.

Under New York law, a “lobbyist” includes a person or organization retained, employed or designated by any client to attempt to influence legislation or its approval or disapproval by the governor.

New York’s Joint Commission on Public Ethics, which governs lobbying rules, did not comment on Artists Against Fracking, instead referring the AP to the law for clarification.

Fracking is a contentious issue in New York, which contains part of the Marcellus Shale region, one of the biggest natural gas reserves in the country. A moratorium on the practice has been in place since 2008, and the Assembly voted earlier this month to extend the ban for two more years.

Gov. Cuomo has said he will not decide on the ban until a report by the state’s health commissioner is released.