The home page of the Hawaii site was replaced with a page of white text on a black background that contained various political and social statements, including the phrase "violate-the-state."
Separately, there were reports that Network Solutions, which once enjoyed a government-sanctioned monopoly on the registration of the most common domain names, had again been hacked. The site, which appeared as normal today, was hacked late last week.
Also last week, hackers vandalized the Web page of the top U.S. weather agency's storm prediction center. The page had to be shut down, which blocked the Internet weather warnings of the Storm Prediction Center, an arm of the National Oceanic and Atmospheric Agency (NOAA).
The day before that attack, the U.S. Army said it launched an investigation into an electronic break-in of its main Web site. The hackers did not breach military security or operations.
A hacker group also broke into four Agriculture Department Web sites at the end of last month. And in May, hackers struck Web sites operated by the FBI and the Senate, causing both to be shut down.
The Senate site was defaced, while the FBI suffered a denial-of-service attack in which attacking computers coordinated a series of requests that overwhelmed the server's capabilities, effectively shutting it down.
The attack on the FBI raised speculation that hackers were retaliating for recent actions by the Houston division of the FBI against suspected criminal hackers. The Houston FBI said in May that it confiscated a number of computers just prior to the Web site attack.
Defense Department and White House Web sites also have been attacked in recent months.