The Anti-Defamation League released a statement condemning the " defacement and destruction of property . " In November 2008 , the United States Postal Service delivered envelopes containing white powder to the LDS Church 's temples in Los Angeles and Salt Lake City and to the national headquarters of the Knights of Columbus in New Haven , Connecticut , prompting a hazardous materials response and a federal domestic terrorism investigation . The envelope to the Knights of Columbus had a postmark from California . Both organizations were heavy backers of Proposition 8 . The FBI has determined the substances were not biological agents , and FBI spokesman Special Agent Juan Becerra stated , " We 've got to follow the evidence , and at this point we have not received anything that would lead us to believe the opponents of Prop. 8 are behind any kind of terroristic activity . It would be irresponsible to say that at this point . " ( Anthrax toxin was used in the 2001 anthrax attacks against lawmakers and media members , killing five people . Since then , the FBI has investigated more than 1,000 anthrax hoaxes modeled on the mailings , which usually turn out to be harmless . ) The LDS Church blamed opponents of the marriage ban for sending the hoax mailings . LGBT rights groups , such as Equality Utah and Equality California , have spoken out against the use of violence in protests , and note that the source of the " white powder " mailings has not been determined
2001 anthrax attacks
2001 anthrax attacks
Protests against Proposition 8 supporters