An affiliate of the hacking activist group Anonymous later claimed responsibility for the May 20 crash of the Chicago City Council website.
Tampa, Florida -- The Republican National Convention is expected to attract an estimated 15,000 protesters in August. But security experts warn officials will need to be prepared for more than just protesters on the streets, they'll also need to be ready for cyber attacks by hacktivists.
"What started out 5 to 10 years ago as a small campaign against organizations involved in animal research and environmental issues has now expanded to now include law enforcement agencies, government agencies as well as financial institutions," said Daryl Johnson, the owner of DT Analytics a private consulting firm that deals with domestic terrorism.
Johnson points out while Tampa officials were in Chicago last month watching how law enforcement handled protesters at the NATO summit, the Chicago Police Department's website suffered a cyber attack.
"So basically they tried to shut down the website as a sign of gaining control over the government's communications tool," Johnson said of the hackers.
Published reports also say the Chicago City Council website was inoperable for a time on May 20. An affiliate of the hacking activist group Anonymous later claimed responsibility.
Security experts tell 10 News hacktivists could target everything from city websites to trying to disrupt cell service and electricity during the GOP convention.
The FBI declined to talk about the issue of hacking during the convention while a spokesperson for the Tampa Police Department would only say it's an issue they are aware of and prepared for.
Calls to the U.S. Secret Service on the subject were not returned.
The Republican National Convention is scheduled to begin on Aug. 27 in Tampa.