The main websites of both the US Republican and Democratic parties were broken into just as the country's citizens were preparing to cast their votes for the next president.
Late Monday, the site of both the Republican National Committee (RNC) and the Democratic National Committee (DNC) were attacked.
In the more serious attack, hackers replaced the RNC website (www.gop.org) with a 1000-word diatribe attacking Texas Governor George W Bush and included a link to the campaign website of US Vice-President Al Gore.
A mirror of the message can be read here.
Republican officials accused their political opponents of dirty tricks. However, the Democrats themselves came under attack. DNC officials confirmed that the party's site was taken down because hackers were repeatedly targeting it.
Both sites were returned to normal by Tuesday afternoon, as the country went to the polls.
Richard Stagg, senior security architect at Information Risk Management, said it is always possible to properly secure a website and prevent defacement.
US parties should have expected to be attacked and the failure of administrators to secure such high-profile sites is, Stagg said, simply "lazy".
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