The FBI Denver Division says that it has seen its main number spoofed in this manner recently, as well as the numbers of its offices in Colorado and Wyoming.
Laramie County District Attorney Jeremiah Sandburg says the Cheyenne Police Department asked the FBI for help with investigating sex trafficking in the city earlier this year.
Ten people were arrested at a Cheyenne hotel late Friday night as part of Operation Cross Country X, an FBI-led initiative focused on recovering underage victims of prostitution.