New York (CNN) -- "Fatwa on your head?" a new series of provocative ads on New York City buses asks. "Is your community or family threatening you? Leaving Islam?"

The ads, sponsored by an organization called Stop the Islamization of America (SIOA), direct viewers to refugefromislam.com, a website designed "for people who are thinking of leaving Islam or are leaving Islam and need resources" to protect them from harm.

Practicing Muslims who find the ads offensive should "ignore it," SIOA leader Pamela Geller told CNN. "It's not directed to them."

Speaking on conservative Sean Hannity's radio show recently, Geller said, "it's time for Americans to stand up against the evil of Islamic jihadi terrorism and Islamic supremacism." The SIOA, which is funded by its online readership, is currently lobbying to block a mosque proposed near the World Trade Center site.

The Council on American-Islamic Relations in New York says the ads are nothing more than "Islam bashing."

"Islamophobes are notorious for their cheap tactics that seek to marginalize American Muslims and divide communities," CAIR Community Affairs director Faiza Ali said in a statement.

"Pamela Geller uses the same tactics as tobacco companies, hiding the cancerous nature of her agenda behind a smokescreen of feigned concern. Geller is free to say what she likes, just as concerned community members are free to critique her tactics and motives," Ali said.

Speaking at a Tennessee "Tea Party" convention earlier this week, Geller called CAIR an "unindicted co-conspirator Muslim-brotherhood front Hamas-tied" organization.

Although the same campaign caused controversy when SIOA bought ad space on public buses in Miami, New York Metropolitan Transit Authority spokesman Aaron Donovan told CNN that no one has asked the MTA to remove the ads yet.

"We have not gotten complaints on it, to be honest," he said. Like most ads seen on MTA subway cars and buses, the campaign will run a month. Last April, Donovan remembered, the MTA ran ads for whyislam.org -- an organization which encourages visitors to explore the Quran and seeks to "challenge popular stereotypes and misconceptions about Islam" -- on the subway system.