Two billboards meant to attack the presidential candidates' religious beliefs were taken down ahead of the Democratic National Convention.
American Atheists placed the billboards in Charlotte, N.C., at the site of the convention in hopes of recruiting others to join its "reasonable" movement.
But after receiving what it called "a large volume of threats," the group decided to nix the billboards.
One of the ads featured a piece of toast with an image of Jesus on it and called Him a "useless savior."
The billboard attacking Mormonism claimed the religion "believes God is a space alien" and "baptizes dead people."
The company that put the billboards up for American Atheists said it supports the right of free speech, but the atheist group agreed to take down its message after public protests.
In response to the opposition, American Atheists Managing Director Amanda Knief said, "No subject, no idea should be above scrutiny - and this includes religion in all forms."
She added that the group is "saddened" by the negative response it received for "questioning the religious beliefs of the men who want to be our president."
American Atheists also wanted to put the billboards up in Tampa, Fla., before the Republican National Convention but no company would lease the group ad space.