"What they don't have the right to do is harrass and intimate people," Protect Marriage spokesperson Frank Schubert said.
Thursday, packets of white powder were sent to two Mormon temples; church leaders had supported Prop 8.
That night, hundreds of protestors marched through downtown Palm Springs.
Saturday, more protests are planned at city halls across the state.
On the Internet, opponents of the ban have been looking up the names of people who donated to the "Yes on 8" campaigns, and on Web sites like Yelp, they are calling for boycotts of businesses that backed the measure.
Pet groomer Michelle Maxwell calls it harassment.
"When you say it's on the Internet people can look at my business and say some derogatory things about me; my vote has nothing to do with my ability to groom dogs," Maxwell said.
Boycotts over political votes are not new. In 1994, Hispanic organizations called for a boycott of Disney (which owns ABC7) because at the time, Disney executives had contributed to the Gov. Pete Wilson, who was campaigning against illegal immigration.
"If you're trying to make news and throw a tantrum, it accomplishes that," Wilson said.
But boycotts should not have an effect on the outcome of Prop 8, Wilson said, that will likely be decided by the state Supreme Court. Three cases have been filed against the measure, including one by San Francisco City Attorney Dennis Herrera. Herrera says same-sex marriage is a civil rights issue and should not be decided by a majority vote.
"The decisions of courts to protect the rights of minorities has never been subject to public referendum," Herrera said. "That's the exact purpose that we have an independent judiciary to protect the minority from the tyranny of the majority."