Anthrax

disease caused by Bacillus anthracis

http://en.wikipedia.org/wiki/Anthrax_disease

Anthrax most commonly occurs in wild and domestic herbivores, but it can also occur in humans when they are exposed to infected animals, tissue from infected animals, or high concentrations of anthrax spores. Still there are no case of people who got sick through contact with a diseased person.

Shortly after the World Trade Center attacks on Sept11'2001, letters containing anthrax Bacteria were sent to five media offices and two US Senators. To date, no individual or group has been charged with the attacks themselves.

http://en.wikipedia.org/wiki/2001_anthrax_attacks