By David Kravets

SAN FRANCISCO - A group of voters sued the state of California and 18 counties on Tuesday in a bid to prevent those counties from using Diebold Election Systems' electronic voting machines in November's general election.

The group Voter Action filed the lawsuit in San Francisco Superior Court alleging that Diebold's touchscreen voting machines lack adequate security and aren't easily used by the disabled.

Machines made by Diebold Election Systems, based in Allen, Texas, are slated to be used in as many as 18 of California's 52 counties this November.

"We can't have trustworthy elections with Diebold's touch-screen voting machines," said Lowell Finley, an attorney representing about a dozen voters. "They are easily hacked."

Last month, California Secretary of State Bruce McPherson gave conditional approval to use the disputed voting machine - the AccuVote-TSX.

The Secretary of State's office said in December that the Diebold machines failed one of the 10 criteria he established for voting machines because the source coding, or computer language, on their memory cards was not reviewed by independent investigators.

But McPherson authorized the machines as long as counties take security precautions, including keeping a written log of who has control of the machines' memory cards.

McPherson spokeswoman Jennifer Kerns said the devices "are safe for use."

Diebold spokesman David Bear said there are 50,000 of the disputed models used in Utah, Mississippi, California and "a spattering of other states."

"The system has been thoroughly tested," Bear said.

Diebold is one of four electronic voting companies McPherson has allowed to operate in California.

State Sen. Debra Bowen, D-Redondo Beach, the chairwoman of the Senate Elections, Reapportionment & Constitutional Amendments Committee, said, "The secretary of state gave Diebold the green light to sell its machines in this state even though its machines don't meet the standards we put into law."

No court date has been set for the lawsuit.

The suit names the counties of Alameda, Fresno, Humbolt, Kern, Lassen, Los Angeles, Marin, Mendocino, Modoc, Placer, Plumas, San Diego, San Joaquin, San Luis Obispo, Santa Barbara, Siskiyou, Trinity and Tulare.

The case is Holder v. McPherson, 06-506171.