Among the groups profiled are such well-known anti-gay heavy hitters (also taken to task here in Fannie's Room over the years) as American Family Association, Americans for Truth [sic] About Homosexuality, Concerned Women For America, MassResistance, and the National Organization for Marriage.
Family Research Council (FRC) President Tony Perkins has called SPLC's actions a "smear campaign" against conservatives while the National Organization for Marriage's Brian Brown has called it an attempt to "marginalize and intimidate" those who oppose same-sex marriage.
According to the SPLC report:
"[I]n March 2008, [Peter] Sprigg [who is a FRC senior research fellow], responding to a question about uniting gay partners during the immigration process, said: 'I would much prefer to export homosexuals from the United States than to import them.' He later apologized, but then went on, last February, to tell MSNBC host Chris Matthews, 'I think there would be a place for criminal sanctions on homosexual behavior.' 'So we should outlaw gay behavior?' Matthews asked. 'Yes,' Sprigg replied. At around the same time, Sprigg claimed that allowing gay people to serve openly in the military would lead to an increase in gay-on-straight sexual assaults."
Of NOM, SPLC writes:
"For a time, NOM’s name was used by a bus driver named Louis Marinelli, who drove a van for NOM’s 'Summer for Marriage Tour' this year. Marinelli called himself a 'NOM strategist' and sent out electronic messages under the NOM logo that repeated falsehoods about homosexuals being pedophiles and gay men having extremely short lifespans (see story, p. 32). In homemade videos posted on his own YouTube page, he said same-sex marriage would lead to 'prostitution, pedophilia and polygamy.'" But this July, NOM said it was not associated with Marinelli."
Personally, reading through the activities and messaging of the listed anti-gay groups, I think their own words indict them.