Researchers at Princeton six months ago demonstrated that Diebold machines can be broken into either through copied keys or simple lock picking. After breaking into the machine, a virus can then be inserted which will rig the vote - and due to the lack of a paper trail no evidence is left.
In another impressive feat of stupidity, Diebold have now put images of the keys up on their website, which as shown below can be used to create working keys:
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