The Motion Picture Association of America (MPAA), which is the group that decides movie ratings in the U.S., has suspended its rating for the horror film Captivity because it ran explicit ads for the movie.

To promote “Captivity,” After Dark submitted ads showing explicit images of a woman’s torture and death. MPAA “summarily rejected” the ads, according to Marilyn Gordon, the org’s senior VP for advertising. But After Dark used the ads anyway, posting them prominently on billboards in highly trafficked areas of Los Angeles as well as in Gotham taxis.

“The sanctions in this case are severe because this was an unacceptable and flagrant violation of MPAA rules and procedures,” Gordon said in a statement.

Public reaction to the billboards was strong, as MPAA switchboards lit up with complaints as well as questions about what to do, an org official said. When MPAA ordered After Dark to remove the ads, the company responded slowly, eventually complying but replacing the original ads with a sign reading “Captivity was here,” as if to have the last word. Ads at bus shelters in L.A. were still displayed Thursday.

Sanction comes in response to After Dark’s “prominent display in both Los Angeles and New York of advertising that the MPAA had explicitly disapproved as inappropriate for general public viewing,” the org said Thursday in a statement.