The Web site for a company whose e-voting machines have come under fire from election officials in New Jersey was hacked Thursday morning, according to an computer scientist who was asked to investigate voting-machine discrepancies in the state's primary election.

The "Ballot Blog" portion of the Sequoia Voting Systems Web site had no content early Thursday afternoon Eastern Standard Time (EST), and earlier in the day there were messages on the page that it had been hacked, Princeton computer science professor Edward Felten told the IDG News Service in an e-mail Thursday. Felten, a critic of e-voting systems, had been asked by a group representing New Jersey county clerks to examine Sequoia machines used in a Feb. 5 New Jersey presidential primary election.

In his e-mail, Felten said that around 6:30 a.m. EST, the Ballot Blog, in which Sequoia gave an in-depth explanation of what had gone wrong in New Jersey, had been replaced with a message saying it had been hacked. He said the message named those who were responsible for the hack, but he could not remember what that name was other than "it was a mixture of lower-case letters and numbers."

By mid-morning, the site had been taken offline by its Web-hosting provider and redirected to a hosting-provider page that said the page had been suspended temporarily for maintenance.

"My guess is that the took the site down temporarily while they were clearing out the stuff left behind by the intruder," Felten said.

Eventually, the blog page returned to its normal appearance Thursday afternoon, but there was still no blog content on the site. Sequoia did not respond immediately to requests for comment.

Sequoia has come under scrutiny for discrepancies in the voting tallies generated by approximately 60 of the state's Sequoia Voting Systems AVC Advantage e-voting machines during last month's election. On Wednesday, a group representing clerks from a half-dozen New Jersey counties wrote to State Attorney General Anne Milgram asking her to investigate the problems.

In most cases, the discrepancy involved a one- or two-vote difference between the paper tape logged by the machine and the number of votes stored in the machine's memory cartridges. Sequoia blamed the discrepancy on poll worker error and said the problem could be fixed with a software update, but state clerks requested a third-party investigation.

The IDG News Service is a Network World affiliate.