Hackers allegedly gain access to the Buckeye Firearms Association's website, causing it to crash, Wednesday night, The Columbus (Ohio) Dispatch reported.
Members had received threats before the system crashed, Ken Hanson, the association's legislative director, said.
The incident occurred days after the group raised $12,000 -- far beyond an original goal of $1,000 -- to send to Zimmerman, who was acquitted July 6 of second-degree murder in the 2012 slaying of teenager Trayvon Martin in Florida.
"It doesn't take a leap of faith to say this is related," Hanson said of the hacking. "It was in response to the fundraiser."
Association Chairman Jim Irvine said members knew aiding Zimmerman would be controversial.
"We've heard from some of our supporters who said, 'Hey, you shouldn't be getting involved with this.' But the majority said, 'Thanks for stepping up,'" Irvine said.
All of the money was sent to Zimmerman, whose gun has been confiscated by the U.S. Justice Department as part of its civil-rights investigation into the shooting.
Excess funds may be used for a security system or to help with Zimmerman's legal bills, the foundation said.
"It wasn't about publicity. It was about helping someone who needed it," Irvine said.