After receiving a request from a controversial anti-Islam group looking to buy ad space in its vehicles and stations, the Washington Metropolitan Area Transit Authority recently announced it would not allow any political or issue-based advertisements for the rest of the year.

According to The Hill, the Metro board agreed to pull all political, religious and other issue ads after Pamela Geller, an anti-Islam activist, announced she would be buying Metro ad space to display cartoon drawings of the Prophet Muhammad, whose depiction is forbidden by Islamic law. The drawings, part of the anti-Islam group’s “Draw Muhammad” contest, have already sparked a shooting in Texas.

“In the coming months, Metro will fully consider the impact that issue-related advertisements have on the community by gathering input from riders, local community groups and advocates,โ€ spokesman Michael Tolbert said in a statement. โ€œMetro will also carefully examine the legal concerns related to displaying, or discontinuing the display of, issue-related advertisements.โ€

For political groups and even the politicians themselves, being unable to advertise on the capital’s public transport system could be enough to cripple a major campaign — mobile advertisements like bus and car wraps and billboards reach more than 95% of Americans.

For the capital transit system itself, turning away millions of dollars in ad revenue could be equally crippling. According to the Washingtonian, political advertisements make up a major chunk of Metro’s ad revenue, and refusing this revenue will make the agency even more cash-strapped than it was before the ban. However, when compared to the $48 million in parking fees and $835 million in passenger fares that Metro brings in each year, the transit authority’s $20 million in yearly ad revenue is a tiny part of its budget.

Geller serves as the head of the American Freedom Defense Initiative (AFDI), which has been classified as an anti-Muslim hate group by the Southern Poverty Law Center. In 2012, a federal judge ruled that the transit systems of both Washington and New York couldn’t refuse to run AFย DI ads emblazoned with an anti-Islam message.

The Metro board will evaluate whether or not to continue its ban at the end of the year.