Diebold Inc. sent a letter to HBO Chief Executive Chris Albrecht expressing concern about "Hacking Democracy," an 81-minute film debuting Thursday night that claims the company's voting machines can be tampered with and can manipulate election results.

Diebold Elections Systems President David Byrd wrote that the documentary incorrectly says that the North Canton-based company's machines counted more than 40 percent of the votes cast in the close 2000 presidential election and that the machines wrongly subtracted or added votes.